System and method to improve plant growth

A system and method to facilitate the growth of a plant in a building. The system includes a substrate that is substantially solid, an inflatable raft, or that has an upper member and a lower member with a space therebetween to establish an interior of the substrate. Either form of substrate includes one or more plant retainers and a set of one or more gaseous fluid delivery ports located regularly or irregularly throughout the substrate, including localized in a vicinity of each of the one or more plant retainers. The system further includes a climate delivery subsystem including a gaseous fluid source, a gaseous fluid delivery apparatus, such as a pump and one or more conduits in the substrate, wherein each of the one or more conduits is in communication with each set of the one or more gaseous fluid delivery ports for delivery of the gaseous fluid to an underside of the plant, wherein the one or more conduits are coupled to the gaseous fluid delivery apparatus.

FIELD OF THE INVENTION

The present invention relates to utilizing modified growing infrastructure to economically regulate a plant's microclimate in controlled environment agriculture (CEA).

BACKGROUND OF THE INVENTION

CEA is defined by its pursuit of growth optimization through the use of equipment to separate plants from volatile outdoor conditions. Generally, the result has been some form of control system actuating equipment, in a greenhouse or other building, to control the general environmental conditions of the space. Despite the considerable gain in efficiency over conventional field production, this too can be rife with inefficiency. Plants often take up a small percentage of overall volume, but the entire environment is typically conditioned for plant growth. Resources are expended on controlling the humidity, temperature, and carbon dioxide concentration (among other things) of the space as a whole rather than focusing on the microclimate of the plant. This microclimate is an area proximal to the plant that can often differ substantially from the overall climate due to plant gas exchange and boundary layer effects. CEA operators often deal with this microclimate by working to dissipate it using horizontal or vertical air circulation to disturb the space. This mixes the air of the general environment with the microclimate to remove boundary layers of environmental variables that may build. The present innovation seeks to give CEA operators a different way of handling the plant's microclimate. Instead of simply mixing in air from the general environment, our innovation seeks to add another layer of control for a CEA operator. The precision added by microclimate control could significantly reduce resources dedicated to carbon dioxide enrichment, humidity, temperature control (among other things). This may improve plant growth and reduce the cost associated with growing each plant.

SUMMARY OF THE INVENTION

The goal of the present invention is to substantially improve the economic and resource efficiency of CEA operations using the microclimate control system and method of the present invention. This is done by redesigning the growing infrastructure to accommodate microclimate monitoring and implementation. The system and method establish, maintain and modify as needed the microclimate adjacent to each plant within a building. The system is an apparatus and associated control functions to create and regulate the climate in the vicinity of each plant. The apparatus includes a substrate for removably retaining plants thereto and one or more components for transferring desired climate elements to each plant retained by the substrate.

The invention enables the mass modification of a plurality of microclimates in that the system can be employed to adjust gaseous fluid delivery on a relatively large scale to adjust the microclimates around a plurality of plants, rather than making such adjustments individually and rather than adjusting the macro climate. For purposes of describing the present invention, a microclimate is not of any specific dimensions but is instead defined as a zone or volume that experiences a measurable modification resulting from the output of an individual plant. It is that zone or volume that the present invention impacts through local gas exchange with the plant. That exchange may occur at the underside of the plant. On the other hand, a macro climate is the broader environment within a structure that contains growing plants that essentially treats plants from the top down. To the extent any underside treatment occurs, it is incidental or not targeted with adequate accuracy or resolution.

The transfer components include a climate delivery subsystem and a microclimate control subsystem. The climate delivery subsystem provides a pressurized gaseous fluid, such as air but not limited thereto, through one or more conduits that are part of the growing infrastructure. The gaseous fluid transfer to the plant is regulated by the microclimate control subsystem to establish microclimate conditions at each of a plurality of plants deemed proper for each plant's growth. The pressurized gaseous fluid flows through the one or more conduits of the connected growing infrastructure to the growing area and contacts the plants from underneath. More generally, the microclimate control subsystem may form part of a larger climate control system that can be used to regulate conditions throughout the environment within which a plant is located. That is, the climate control system may be used to adjust conditions within a structure, such as a greenhouse, including, but not limited to, heating, ventilation and air conditioning, as well as humidity control, and water delivery.

This allows us to shrink the area that needs to be tightly regulated for plant growth proximal to the plants and results in the modified environment contacting the underside of plant leaves. Given that the underside of the plant leaves is where the bulk of gas exchange occurs, this provides an advantage for carbon dioxide enrichment and dehumidification (among other things). The leaves also help provide a boundary layer to trap this modified atmosphere near the stomata of the plant. Ultimately, this should reduce considerably the magnitude of resources spent on atmospheric control for the plants in the building. These advantages can be seen from the following detailed description and the accompanying drawings.

The invention includes a system to facilitate the growth of a plant in a building. The system includes a substrate with one or more plant retainers of the upper member and a set of one or more gaseous fluid delivery ports located in a vicinity of each of the one or more plant retainers or positioned throughout the substrate and not limited to being solely adjacent to the plants, and a climate delivery subsystem including a gaseous fluid source, a gaseous fluid delivery apparatus, such as a pump or a combination of components suitable to controlling gaseous fluid condition and delivery, and one or more conduits in the space between the upper member and the lower member of the substrate, wherein each of the one or more conduits is in communication with each set of the one or more gaseous fluid delivery ports for delivery of the gaseous fluid to an underside of the plant, wherein the one or more conduits are coupled to the gaseous fluid delivery apparatus. The system optionally also includes a microclimate control subsystem, wherein the microclimate control subsystem includes a processor programmed to regulate operation of the gaseous fluid delivery apparatus and one or more atmosphere sensors arranged to gather information about a microclimate in the vicinity of the plant to aid in regulation of operation of the gaseous fluid delivery apparatus. The microclimate control subsystem may form part of a larger climate control system. The substrate may be a unitary structure and may include an inflatable raft-like structure, or it may be formed of a top piece that is the upper member connected to a bottom piece that is the lower member. In the non-unitary form, the bottom piece may be a pitched trough. In a form of the substrate, it may have an upper member and a lower with a space between them. The space is open and the one or more conduits is a single conduit that is the open space. In another form, the substrate includes one or more dividers in the space between the upper member and the lower member, wherein the one or more dividers establish two or more channels in the space and wherein the two or more channels are the one or more conduits. The delivery subsystem may include a plurality of tubes coupled to the gaseous fluid delivery ports, wherein the plurality of tubes are the one or more conduits. At least one of the gaseous fluid delivery ports may include a nozzle. The nozzle may be configured to form a selectable spray pattern of the gaseous fluid about the plant retainer.

The invention also includes a method for establishing a microclimate in the vicinity of a plant. The method includes the steps of inserting one or more plant seedlings or root elements into one or more plant retainers of a substrate, delivering with a climate delivery subsystem a gaseous fluid to one or more of the ports adjacent to the one or more plant retainers, sensing environmental conditions in the microclimate associated with each of the one or more retainers and adjusting delivery of the gaseous fluid as a function of the sensed environmental conditions. The substrate and the delivery subsystem may be of the form described herein. The gaseous fluid includes carbon dioxide content. Delivery of the gaseous fluid includes delivering the gaseous fluid directly throughout the interior of the substrate, through one or more channels and/or through one or more conduits.

A version of the system contemplates a substantially solid substrate that includes one or more plant retainers and a set of one or more gaseous fluid delivery ports located in a vicinity of each of the one or more plant retainers. It also includes a climate delivery subsystem including a gaseous fluid source, a gaseous fluid delivery component and one or more conduits in communication with each set of the one or more gaseous fluid delivery ports for delivery of the gaseous fluid to an underside of the plant, wherein the one or more conduits are coupled to the gaseous fluid delivery component. For example, in an embodiment of the invention, the substrate may be an inflatable buoyant material that is similar to a raft made of a nonmetallic material such as a plastic. This form of substrate may include one or more ports for retaining one or more plants therein.

DETAILED DESCRIPTION OF THE INVENTION

A first embodiment of an efficient plant growth system10of the present invention is shown inFIGS.1,2and4. The system includes a plant retaining substrate12, a climate delivery subsystem14and a microclimate control subsystem16. The substrate12, climate delivery subsystem14and the microclimate control subsystem16are used in combination to deliver a desired atmosphere18to underside20of a plant22that is growing in a building.

The substrate12is fabricated of a material that either floats on or that is retained in position on a surface24. The surface may be solid or it may be a fluid26such as water, for example. The substrate12is made of a nonmetallic material such as polyethylene or polypropylene plastic but not limited thereto. The substrate12is made with sufficient structural integrity to minimize flexing or other undesirable distortion and to support a plurality if plants retained thereto. The substrate12will also maintain a positive buoyancy while on the fluid26and while containing contents of interest, such as a plurality of the plants22as well as components of the climate delivery subsystem14and the microclimate control subsystem16. However, such positive buoyancy is not required if the surface24is solid rather than the fluid26.

The substrate12may be in a rectangular form but other configurations are possible. A plurality of such substrates12may be positioned adjacent to one another, such as in a trough, for example. The trough may contain the fluid26, which may be used as a mechanism for easily moving each substrate12from one location to another, or the trough may contain no fluid. A plurality of substrates12may be joined together or they may be independent from one another. In an example shown inFIG.5, the substrates12are joined together in series with a common coupling15used to complete the transfer of gaseous fluid from the inlet56. All can be moved in the trough including when on the fluid26.

The substrate12includes a plurality of plant retainers30, each of which is sized and shaped to retain growth matter, such as liquid, soil or a combination of the two, as well as seedlings or a preliminary root system. The retainers30may be porous with pores32sufficiently large to allow the fluid26to pass therethrough. Alternatively, the pores32may be relatively smaller so that the retainer30may retain soil therein while also allowing some of the fluid26to seep in and maintain soil moistness suitable for plant growth. The retainers30may simply be cutouts of the substrate12at selectable locations or they may be removable containers positioned at selectable locations of the substrate12.

The substrate12also includes one or more gaseous fluid delivery ports34. The ports34are located near the retainers30at a selectable distance so that a microclimate of interest is established in the vicinity of the plant22. The number of ports34and their positioning about the retainer30is selectable. The ports34are sized and configured to allow gaseous fluid to pass therethrough and form a pattern of the gaseous fluid that contacts the underside of the plant22. Alternatively, the ports34are sized and configured to removably retain therein a gas delivery nozzle36. Each such optional nozzle36forms part of the climate delivery subsystem14. The nozzles36are configured with fluid flow ports38that are sized, spaced and shaped to deliver a selectable pattern of flow of gaseous fluid of a desired makeup to the space in the vicinity of the plant22in the area of the underside20of the plant22but not limited thereto. That is, the optional nozzles36are positioned to deliver desirable gaseous matter in the location of the plant22rather than in the general atmosphere in the building above the plant22. Whether using the ports34directly or the nozzles36to deliver the gaseous fluid to the undersides of the plants, the ports or nozzle outlets are relatively small to deliver a fine spray of gaseous fluid that enables fine resolution of the microclimate about the plants, rather than a larger delivery port that may blast large volumes about the plants in a way that does not establish a microclimate that remains in effect. For example, a delivery port that is measured in inches rather than fractions of an inch are much less suitable as a feature of the present invention.

The climate delivery subsystem14includes a gaseous fluid source38, one or more gaseous fluid delivery apparatuses40, one or more manifolds42and one or more conduits for delivery of the gaseous fluid from the source38to the interior of the substrate12. The source38may be a single tank of a gaseous fluid such as air, nitrogen, carbon dioxide or combinations of those and/or other gases that may be of interest for delivery to the plant22. The source38may also be a condenser of some form that captures and concentrates gases of interest from the atmosphere. The source38is shown as a single element but that is simply a representation of what may be one or a plurality of gaseous fluid sources.

The source38is coupled to the one or more gaseous fluid delivery apparatuses40, which are represented in the drawings as a single pump40. The gaseous fluid delivery apparatus40is selected and configured to deliver a regulated volume of gaseous fluid from the source38to the one or more manifolds42, which is represented as a single manifold42. The gaseous fluid delivery apparatus40is also coupled to the microclimate control subsystem16arranged to control operation of the gaseous fluid delivery apparatus40for regulation of gaseous fluid flow to the manifold42. The gaseous fluid delivery apparatus includes an input44and an output46. The input44is coupled by source conduit48to an output of the source38. The source conduit48may be tubing, such as metallic or nonmetallic tubing, including plastic tubing, suitable to transport gaseous fluid. The gaseous fluid delivery apparatus40may comprise one or more of a heater and/or chiller to heat or cool the gaseous fluid, a gas blending valve for CO2 mixing with air or another fluid, and a humidification/dehumidification mechanism to adjust the humidity of the gaseous fluid prior to delivery to the substrate12, as well as a mechanism for gaseous fluid delivery, such as one or more pumps, blowers or fans. The components of the gaseous fluid delivery apparatus40may be standalone or integrated into a control system that is also linked to one or more environmental sensors so that they may be actuated and adjusted as desired based on sensed conditions below and above the plant22. The control mechanism may be configured to regulate the rate of delivery of the gaseous fluid.

The manifold42includes one or more inputs50and one or more outputs52. A single input50may be used to receive gaseous fluid from a single source, while a plurality of manifold inputs50may be used to receive a plurality of gaseous fluids from a plurality of sources, wherein mixing of the plurality of gaseous fluids occurs in a mixing cavity of the manifold42. The number of outputs52is selectable and is dependent on the number of substrates12to be supplied with gaseous fluid from that manifold42. The manifold input50is coupled to the output46by output conduit54.

The climate delivery subsystem14further includes one or more gaseous fluid delivery portals56of each substrate12. Each portal56includes an input58and an output60. Each input58is coupled to one of the plurality of manifold outlets52, and each output60terminates at, within or beyond an interior wall61of the substrate12. Interior62of the substrate12may be substantially hollow or it may contain a plurality of channels64that run at least a portion of a length or width dimension of the substrate12. When the interior62is substantially hollow, represented inFIGS.1and2, only one gaseous fluid delivery portal56may be established in the substrate12for delivery of the gaseous fluid into the interior62, although more than one portal56may be employed for that delivery. When the interior62includes a plurality of channels64, represented by a second embodiment of the invention inFIG.3, there may be at least one portal56for each channel64, although each channel64may have more than one corresponding portal56. The channels64function as conduits for gaseous fluid flow regulation. The gaseous fluid delivery apparatus40delivers the gaseous fluid to the portals56at sufficient pressure to ensure that the gaseous fluid enters the hollow interior or the channeled interior and vents through the ports34with or without nozzles36at sufficient rate to establish the microclimate at least at the underside of the plant22.

In the second embodiment of the invention shown inFIG.3, the climate delivery subsystem14may include a series of conduits, which may be tubes, that are coupled between the gaseous fluid delivery portals56and the ports34or nozzles36. That configuration may result in the use of less gaseous fluid for direct delivery to the plants22; however, they represent more infrastructure to be purchased and maintained and so may be less convenient and more costly overall. It is to be understood that one or more valves may be employed at one or more locations between the gaseous fluid delivery apparatus40and the portals56to enable localized manual control of fluid movement to the plant22. The conduits in the second embodiment described herein may pass over, under or through the substrate12in any combination.

In a third embodiment of the invention shown inFIGS.6and7, the substrate12is formed of two separate pieces, a top piece100and a bottom piece102. The top piece100and the bottom piece102may be permanently or removably joined together. They may also be formed integrally with one another. This form of the substrate12may be referred to as a double-walled construction. Space104between the top piece100and the bottom piece102may be completely or substantially hollow, it may contain elements to maintain structural integrity, such as ribs, or it may be formed with a plurality of interior channels that are similar to the channels64of the first embodiment of the invention. The bottom piece102may be U-shaped or V-shaped. When V-shaped, there is a pitch to sidewalls106that can concentrate water and other items in bottom piece102. The interior of either or both of the top piece100and the bottom piece102may be modified to include attached or integrated conduits used to transport gaseous fluid to gaseous fluid delivery ports108that extend at least partially around plant retainers110of the top piece100. It is noted that the plant retainers110may be optional, with plants supported in a different manner at the top piece100. Either or both of the top piece100and the bottom piece102include one or more portals114, each having an input116and an output118. Each input116is coupled to one of the plurality of manifold outlets50, and each output118may terminate at, within or beyond the end cap112. Each output118may be open to the interior104of the substrate12, whether the substrate12is open, channeled or otherwise contains a plurality of conduits. Each output118may also be coupled to a conduit, such as a tube, that is joined directly or indirectly to the delivery ports108of a particular plant.

A variant of the third embodiment of the invention relates to aeroponic plant growth. A plant support structure similar to that shown inFIGS.6and7. In an aeroponic process, mist rather than liquid water is delivered into the space104. That may be done either with piping that delivers the mist at specific locations or by general delivery throughout the space112. In addition, the top piece100and, optionally, the bottom piece102may be formed of a porous material rather than a solid material. The plants may be grown directly on and through the porous structure and so plant retainers110are not required. In this variant of the present invention for aeroponic operations, the plant support is a porous structure and the portals114through which the gaseous fluid is delivered to the underside of the plant may be accomplished through pores adjacent to the plants. As a result, the present invention may be used to establish a microclimate adjacent to a plant grown in an aeroponic process.

Another variant of the third embodiment of the invention shown inFIG.8includes a top piece120and the bottom piece102. The top piece120is of a double walled configuration wherein there is an upper wall122and a lower wall124. A space126is established between the upper wall122and the lower wall124. The gaseous fluid may be inserted into the space126so that it is forced through portals108extending at least partially around the retainer110. The retainers110are optional when alternative mechanisms for plant retention are employed including, for example, making the top piece at least partially porous. The gaseous fluid may be directed into the space126via portal114. The double walled configuration may also be used in an aeroponic system of the type described above. The substrate may also be an inflatable raft type of structure with plant retainers established therein, as well as multiple gaseous fluid delivery ports, whether distributed adjacent to individual plants or regularly or irregularly distributed throughout the substrate and not necessarily associated with individual plants.

The microclimate control subsystem16includes a processor70, a controller72and a plurality of atmosphere sensors74. The processor70may be any form of computer processing component suitable for receiving atmosphere sensing information from the atmosphere sensors74, delivering operational instructions to the one or more gaseous fluid delivery apparatuses40and capable of programming using control instructions programmed into the processor70. The processor70may be in the form of a desktop computer, a laptop computer, a handheld device such as a tablet or smartphone, or any other device suitable for the intended operation of the system10. The controller72is coupled to the processor70and to the gaseous fluid delivery apparatus40, either by wire or wirelessly. The controller72may be any sort of feedforward or feedback apparatus suitable for regulating operation of the gaseous fluid delivery apparatus40.

The atmosphere sensors74are selected to gather information regarding conditions in the microenvironment of each plant22. The sensors74may be selected to gather information on temperature, humidity, oxygen and carbon dioxide, for example, but not limited thereto. The sensors74are coupled by wire or wirelessly to the processor70. As shown inFIG.9, an example representation of the plurality of the sensors74shows that they may be positioned substantially above the tops of the plants22, near the tops of the plants22and near the undersides20of the plants22. The information gathered at these locations can be used to determine useful information suitable for making plant growth most efficient including, but not limited to, carbon dioxide concentrations at those locations, which information can be used to adjust input from the pump40. The use of a plurality of atmosphere sensors, which may be more than the three in the representative example, at locations under the plant, just above the plant and well above the plant allow the operator to observe the interplay of change in conditions from under the plant up to the more general atmosphere well above the plant. It can be used to determine the directional flow of relevant atmospheric information including CO2 content, either toward or away from the plant representing plant aspiration rate through the zones or strata extending from below to above the plant. That information can then be used to adjust the microclimate adjacent to the plant as well as the larger atmosphere near to and away from the plant. Those adjustments to heat, humidity, light, etc., can be made sooner than would occur if manual observations or made or if sensing occurs at a single location or at a location or locations not adjacent to the plant, thereby optimizing growing conditions.

The microclimate control subsystem16may form part of a larger climate control system and so is not limited solely to operation of the gaseous fluid delivery apparatus40used to deliver the gaseous fluid. For example and without limitation, the larger climate control system may be used to regulate all aspects of the environment containing the plants22including, but not limited to, temperature, humidity, light, nutrient delivery and water delivery. The description herein of the microclimate control subsystem16is not intended to limit environment control solely to that of the gaseous fluid delivery to the undersides20of the plants22. Further, that larger climate control system may be coupled to the sensors74and used to aid in regulation of the environment within the structure.

The system10of the present invention is used to carry out steps of the method of plant microclimate control of the present invention. The method includes inserting one or more plant seedlings or root elements into each of the retainers30located in the substrate12on the fluid26. Dependent on the status of the seedlings or root elements, gaseous fluid is delivered from the source38to one or more of the ports adjacent to the plant22using any of the configurations described herein. The content of the gaseous fluid is selectable and dependent on the condition of the plant22. When the plant22is sufficiently sized to create a canopy over a portion of the substrate12, the content of the gaseous fluid may be adjusted, such as by increasing the carbon dioxide content, for example. The sensors74are employed to detect the microenvironment in the vicinity of the plant22to aid in regulating fluid flow from the source38through the pump to the ports. It is noted that the method may also include delivering the gaseous fluid directly throughout the interior of the substrate12, through one or more channels and/or through one or more conduits as described. It is also noted that the sensors that may be used are not limited to those solely located at or near the plants. Other sensed information may be acquired in the environment and used to regulate that environment.

In an embodiment of the invention, the gaseous fluid delivery ports may be positioned regularly or irregularly around the substrate and not specifically positioned immediately adjacent to the plant retainers. That is, the delivery ports may be dispersed throughout the substrate. In that configuration, the gaseous fluid continues to be delivered near the upper surface of the substrate. Gas movement means within the building containing the invention, such as one or more fans or one or more pumps, for example, can be used to move the gaseous fluid along the substrate to produce a mixing of the gaseous fluid at the underside of all plants retained to the substrate so that there is a sharing and mixing of the gaseous fluid among groups of plants throughout the building. This is effectively a mass modification of the microclimate in the vicinity of all plants. Whereas prior greenhouse systems circulate air throughout the entire building, that circulation substantially does not exist at the local underside of the plants. The present invention resolves that limitation either with concentrated delivery ports or distributed ones.

The present invention conditions the environment at the underside of the plants, either with the immediately adjacent delivery ports described above or with an air-hockey-like arrangement of distributed delivery ports coupled with a circulation mechanism that conditions the atmosphere locally for all plants but does so with a widely distributed gaseous fluid delivery. This embodiment of the invention may be useful in most greenhouse configurations, including those with roof vents wherein mixed gaseous fluid is forced or drawn from the underside of the plants up to the ceiling of the building. The gaseous fluid first makes contact with the underside of the plant before passing upwardly through the building to be vented at the ceiling. This arrangement may be useful for growing lettuce but is not limited thereto.

The system10and related method shrink the area needed for tight regulation of plant growth so that it is proximal to the plant and results in the modified environment contacting the underside of plant leaves before contacting anything else in the building. Given that the underside of the plant leaves is where the bulk of gas exchange occurs, this provides an advantage for carbon dioxide enrichment and dehumidification (among other things). The leaves also help provide a boundary layer to trap this modified atmosphere near the stomata of the plant. The present invention reduces considerably the magnitude of resources spent on atmospheric control for the plants in the building.