MODULAR PLANT GROWTH APPARATUS

Abstract: Plant growth apparatus including a modular growth element comprising a plant growth bed, a connector for connecting to another such growth element, a heating element disposed in the growth element and thermal insulation that insulates at least one face of the growth element, wherein the heating element raises and maintains a temperature of a substantial portion of the growth element to a level which disinfects the growth bed. The growth element may include a drain trough attached to the growth element and in fluid communication therewith.

Description: MODULAR PLANT GROWTH APPARATUS FIELD OF THE INVENTION The present invention relates to multi-tier crop beds generally, and particularly to multi-tier crop beds with soil disinfestation and drainage. BACKGROUND OF THE INVENTION Multi-tiered crop beds are known structures that provide increased area for sowing seedlings and plant growth. Multi-tiered crop beds are generally constructed of soil containers or terraces raised one above another so as to increase the amount of available arable soil for a given plot of flat land. The crop beds may be arranged vertically above each other, staggered or in any other geometrical arrangement. For example, United States Patent 5,428,922 to Johnson describes a planter with a bottom tub with a series of vertical retaining tubes extending therefrom which support a plurality of flared tubs stacked one above another around a sectional central pipe. Spanish Patent 8403272 describes a pyramid shaped structure mounted in a container for cultivating plants in a greenhouse. The structure supports soil for growing plants at a number of different levels with each level partly overhanging the level below it. Soil disinfestation by heating soil with solar energy to control and kill soil pathogens and weeds is well known in the art. The bibliography entitled "The First Decade (1976-1986) of Soil Solarization (Solar Heating): A Chronological Bibliography" in Phytoparasitica 15(3):229-255, 1987, by J. Katan et al, provides a good summary of the activity in the art. SUMMARY OF THE INVENTION The present invention seeks to provide an improved multi-tier crop bed with soil disinfestation and drainage. There is thus provided in accordance with a preferred embodiment of the present invention plant growth apparatus including a modular growth element comprising a plant growth bed, a connector for connecting to another such growth element, a heating element disposed in the growth element and thermal insulation that insulates at least one face of the growth element, wherein the heating element raises and maintains a temperature of a substantial portion of the growth element to a level which disinfects the growth bed. The growth element may include a drain trough attached to the growth element and in fluid communication therewith. In accordance with a preferred embodiment of the present invention, the heating element is sandwiched between at least one layer of a first insulating material and at least one layer of a second insulating material. The insulating materials may include polystyrene, polyurethane, polyvinyl chloride, and polycarbonate. A sheet of thermal radiation reflective material, such as white nylon or polyethylene, may be placed over the growth element to internally reflect thermal radiation and increase a temperature of a substantial portion of the growth element. Additionally in accordance with a preferred embodiment of the present invention, the heating element is substantially flat and dissipates electrical power as heat. Further in accordance with a preferred embodiment of the present invention, there is also provided at least one temperature sensor operating in a closed control loop to control the temperature of the growth bed. In a preferred embodiment of the present invention, there is also provided a tiered support structure including a plurality of support members upon which are placed a plurality of the growth elements. The support members preferably are arranged in a staggered pyramid formation. There is also provided in accordance with a preferred embodiment of the present invention a method for plant growth including modularly connecting a plurality of growth elements together, and raising and maintaining a temperature of a substantial portion of the growth elements to a level which disinfects the growth element. The growth elements may be connected to form a stacked pyramid formation. The method may further include draining excess water from the growth elements. Additionally in accordance with a preferred embodiment of the present invention, the growth element temperature is raised to a temperature which causes pasteurization thereof. Further in accordance with a preferred embodiment of the present invention, the growth bed temperature is raised to a temperature which causes sterilization thereof. In accordance with one preferred embodiment of the present invention, the growth bed temperature is raised to a temperature of approximately 70°C for a duration of approximately at least 3 hours. In accordance with another preferred embodiment of the present invention, the growth bed temperature is raised to a temperature of approximately 60°C for a duration of approximately at least 4 hours. In accordance with yet another preferred embodiment of the present invention, the growth bed temperature is raised to a temperature of approximately 100°C for a duration of approximately at least 3 hours. The soil disinfestation by heating is preferably performed approximately one day to two weeks before planting. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which: Fig. 1 is a simplified pictorial, partially sectional illustration of a modular growth element, constructed and operative in accordance with a preferred embodiment of the present invention; Fig. 2 is a simplified pictorial illustration of a plurality of modular growth elements on a tiered support structure, constructed and operative in accordance with a preferred embodiment of the present invention; Fig. 3 is a simplified pictorial illustration of growing plants on the structure of Fig. 2, in accordance with a preferred embodiment of the present invention; Fig. 4 is a simplified pictorial illustration of a heating element, constructed and operative in accordance with a preferred embodiment of the present invention, and which may be employed with the modular growth element of Fig. 1; Fig. 5 is a simplified pictorial illustration of temperature control apparatus for controlling temperature of a plurality of modular growth elements, constructed and operative in accordance with a preferred embodiment of the present invention; and Fig. 6 is a simplified pictorial illustration of a domestic modular-growth-element tiered support structure, constructed and operative in accordance with a preferred embodiment of the present invention. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Reference is now made to Fig. 1, which illustrates a modular growth element 10, constructed and operative in accordance with a preferred embodiment of the present invention. Modular growth element 10 comprises a growth bed 14, comprising a layer of any conventional growth medium or soil, typically approximately 10-20 cm deep. Depending on the type of growth medium, growth bed 14 may be provided with a housing (not shown) to contain the growth medium, or alternatively, no housing may be required. Underneath growth bed 14 is a heating element 16 which is preferably substantially flat. A thin, thermal insulating sheet 18, typically constructed of polycarbonate or polyvinyl chloride (PVC), may be placed between growth bed 14 and heating element 16. Heating element 16 preferably dissipates electrical power as heat, such as an electric heating blanket which is provided with a suitable protective coating, such as a polymeric coating. Heating element 16 is preferably provided with electrical leads 17 for connection with a power source 19. Underneath the heating element 16 is preferably a layer of a porous medium 20, such as tuff, compost, coconut hairs or polystyrene foam. The layer of porous medium 20 is typically approximately 1-5 cm thick. Underneath porous medium 20 is a layer of thermal insulation 22. Thermal insulation 22 is typically made of a material such as polystyrene, PVC or polyurethane, and is preferably approximately 1-5 cm thick. The layer of porous medium 20 helps to separate heating element 16 from the thermal insulation 22, thereby helping to avoid direct heating damage thereto. Alternatively, additional thermal insulation may be provided above growth bed 14. For example, growth bed 14 may be covered with a layer of thermally insulative material 23, such as a white sheet of nylon or polyethylene. Thermally insulative material 23 internally reflects thermal radiation and increases a temperature of a substantial portion of growth element 14. This helps to promote and maintain a uniform temperature in growth bed 14, as well as provide extra thermal insulation. In accordance with a preferred embodiment of the present invention, at least one temperature sensor 24 is embedded in growth bed 14 and is connected to a controller 26 which is in electrical communication with one of the leads 17 and with power source 19. Temperature sensor 24 and controller 26 operate in a closed control loop to control the temperature of growth bed 14. A drain trough 28 is preferably attached to modular growth element 10 and in fluid communication therewith. Drain trough 28 may be constructed of a suitable engineering plastic and may be attached in any conventional manner to any portion of modular growth element 10. Preferably a connector 30 is provided for connecting one modular growth element 10 to another. Connector 30 may be a clip, VELCRO ® strap, buckle, adhesive, or mechanical fastener, for example. Connector 30 may be attached in any conventional manner to any portion of modular growth element 10. Reference is now made to Fig. 2 which illustrates a plurality of modular growth elements 10 on a tiered support structure 40, constructed and operative in accordance with a preferred embodiment of the present invention. Tiered support structure 40 preferably includes a plurality of support members 42 upon which are placed the modular growth elements 10. Support members 42 are preferably constructed of stiff metal posts or wire, and are preferably arranged in a staggered pyramid formation. As seen in Fig. 2, modular growth elements 10 may be connected and placed upon support members 42 to form a stacked pyramid formation. Drain troughs 28 may be used to drain excess water from growth elements 14. Reference is now made to Fig. 3 which illustrates growing plants 44 in the modular growth elements 10 on tiered support structure 40, in accordance with a preferred embodiment of the present invention. The growth of plants 44 may be enhanced by disinfestation of the growth medium of growth beds 14, in accordance with a preferred embodiment of the present invention, as will now be described. In order to disinfect growth bed 14, heating element 16 is energized to heat growth bed 14 to a temperature which causes the desired level of disinfestation. For pasteurization, the temperature of the growth bed 14 is preferably raised to approximately 70°C for a duration of approximately at least 3 hours. Alternatively, the temperature of growth bed 14 may be raised to approximately 60°C for a duration of approximately at least 4 hours. For sterilization, the temperature of growth bed 14 is preferably raised to approximately 100°C for a duration of approximately at least 3 hours. It is appreciated that the method described herein may be used in conjunction with solarization of the soil. For example, growth bed 14 may be solarized during the day with conventional methods of soil solarization and further disinfestation accomplished with the methods of the present invention during the night or during cloudy days. The soil disinfestation by heating is preferably performed approximately one day to two weeks before planting. It is a particular feature of the present invention that plants may be sown or planted not only on the upper face of growth bed 14 but also on a vertical side of growth bed 14. In such a configuration, for example, leaves 47 of plants 44 growing on the vertical sides of growth bed 14 may tend to develop and point themselves upwards, while at the same time fruit 49, which is generally heavier than the leaves 47, tends to develop downwards. This separation of leaf and fruit (or flower) can be beneficial to fruit/flower development in certain species. Reference is now made to Fig. 4 which illustrates a heating element 50, constructed and operative in accordance with a preferred embodiment of the present invention, and which may be employed with the modular growth element of Fig. 1. Heating element 50 preferably includes one or more discrete, localized heating zones 52. Heating zones 52 may comprise any pattern of electrical resistor elements printed or embedded in a strip 54 of electrically insulative material, such as a plastic. Heating zones 52 may be interconnected in series or parallel and connected to a power source 56 via a bus 58. Alternatively, heating zones 52 may be individually connected to power source 56. Heating elements 50 may be used to heat modular growth elements 10 in tiered support structure 40 of Fig. 3, for example. Alternatively, heating elements 50 may be used to heat individual flower pots or beds. Reference is now made to Fig. 5 which illustrates temperature control apparatus 60 for cooling, heating and/or controlling temperature of a plurality of modular growth elements, such as modular growth elements 10 in tiered support structure 40 of Fig. 3, for example, constructed and operative in accordance with a preferred embodiment of the present invention. Apparatus 60 may comprise any type of air-air heat exchanger, water-air heat exchanger or air-conditioning system or simply a fan or blower. Apparatus 60 preferably includes a fan 62, such as a centrifugal fan, positioned at an end 64 of a housing 66 which envelopes tiered support structure 40. Housing 66, which may be constructed of a transparent plastic, is preferably at least partially open to the outside air at end 64 and may be closed at an opposite end 68. Fan 62 blows air over plants 44, the air entering the inside of housing 66 at end 64 and exiting through openings 70 formed in housing 66 near each plant 44. It is appreciated that fan 62 and openings 70 may be positioned at other places in housing 66 depending on the particular requirements of the plants 44. The flow of air controls and/or raises or lowers the temperature of growth beds 14. Depending on the type of apparatus 60 chosen (i.e., air-air heat exchanger, water-air heat exchanger or air-conditioning system), apparatus 60 may either heat or cool growth beds 14 as desired. As is well known to those skilled in the art of heat transfer, cooling may be enhanced by modifying/controlling a variety of heat transfer parameters. For example, the growth beds 14 may be moistened, thereby increasing heat transfer to the air passing thereover. Reference is now made to Fig. 6 which illustrates a domestic modular-growth- element tiered support structure 80, constructed and operative in accordance with a preferred embodiment of the present invention. Tiered support structure 80 is preferably constructed in the same manner as tiered support structure 40 described hereinabove with reference to Figs. 2 and 3, with like elements being designated by like numerals. Tiered support structure 80 preferably includes a power cord 82 and water supply tube 84 for convenient installment in a house, patio or the like. Power cord 82 is of course connected to a mains (not shown) for supplying electrical power to heating elements 16. Water supply tube 84 is connected to a water supply (schematically designated by numeral 86) for supplying water to modular growth elements 10. Inlet water enters water supply tube 84 and is preferably fed to growth elements 10 via channels formed in walls 88 of tiered support structure 80. Water is drained in drain troughs 28 and, if necessary, an exit water tube 90 may be provided to expel excess water. Tiered support structure 80 is thus a "turn-key" system for domestic use, comprising the heating elements for disinfection of the soil, water for plant growth, drain troughs and any necessary sensors and controllers to monitor and control operation of the growth elements. It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of the features described hereinabove as well as modifications and variations thereof which would occur to a person of skill in the art upon reading the foregoing description and which are not in the prior art.

Claims: C L A I M S What is claimed is: 1. Plant growth apparatus comprising: a modular growth element comprising a plant growth bed; a connector attached to said growth element for connecting one said growth element to another said growth element; a heating element disposed in said growth element; and thermal insulation that insulates at least one face of said growth element, wherein said heating element raises and maintains a temperature of a substantial portion of said growth element to a level which disinfects said growth bed. 2. Apparatus according to claim 1 and comprising a drain trough attached to said growth element and in fluid communication therewith. 3. Apparatus according to claim 1 or claim 2 wherein said heating element is sandwiched between at least one layer of a first insulating material and at least one layer of a second insulating material. 4. Apparatus according to claim 3 wherein said first and said second insulating materials are selected from the group consisting of polystyrene, polyurethane, polyvinyl chloride, and polycarbonate. 5. Apparatus according to claim 1 and comprising a sheet of thermal radiation reflective material placed over said growth element. 6. Apparatus according to claim 1 and wherein said heating element is substantially flat. 7. Apparatus according to claim 1 and wherein said heating element dissipates electrical power as heat. 8. Apparatus according to claim 1 and comprising at least one temperature sensor operating in a closed control loop to control said temperature of said growth bed. 9. Apparatus according to claim 1 and comprising a tiered support structure comprising a plurality of support members upon which are placed a plurality of said growth elements. 10. Apparatus according to claim 9 and wherein said support members are arranged in a staggered pyramid formation. 11. Apparatus according to claim 9 and comprising a drain trough attached to said growth elements and in fluid communication therewith. 12. Apparatus according to claim 11 and comprising a power cord and water supply tube. 13. Apparatus according to claim 1 and wherein said heating element comprises a plurality of discrete, localized heating zones for heating individual plants. 14. Apparatus according to claim 13 and wherein said heating zones comprise a pattern of electrical resistor elements disposed in a strip of electrically insulative material. 15. Apparatus according to claim 13 or claim 14 and wherein said heating zones are electrically interconnected with each other and are connected to a power source. 16. Apparatus according to claim 13 or claim 14 and wherein said heating zones are individually connected to a power source. 17. Heating apparatus for plants comprising a plurality of discrete, localized heating zones for heating individual plants, said heating zones comprising a pattern of electrical resistor elements disposed in a strip of electrically insulative material. 18. Apparatus according to claim 17 and wherein said heating zones are electrically interconnected with each other and are connected to a power source. 19. Apparatus according to claim 17 and wherein said heating zones are individually connected to a power source. 20. Apparatus according to claim 1 and comprising temperature control apparatus for controlling temperature of at least one said modular growth elements, said temperature control apparatus comprising a fan which blows air through a housing which envelopes said at least one modular growth element, said air blowing over said at least one modular growth element. 21. Apparatus according to claim 9 and comprising temperature control apparatus for controlling temperature of said modular growth elements, said temperature control apparatus comprising a fan which blows air through a housing which envelopes tiered support structure, said air blowing over said modular growth elements. 22. Apparatus according to claim 20 or claim 21 and wherein said temperature control apparatus is selected from the group consisting of an air-air heat exchanger, a water-air heat exchanger or an air-conditioning system. 23. A method for plant growth comprising: modularly connecting a plurality of growth elements together; and raising and maintaining a temperature of a substantial portion of said growth elements to a level which disinfects said growth element. 24. A method according to claim 23 and comprising connecting said growth elements to form a stacked pyramid formation. 25. A method according to claim 23 or claim 24 and comprising draining excess water from said growth elements. 26. A method according to claim 23 and comprising raising a temperature of said growth element to a temperature which causes pasteurization thereof. 27. A method according to claim 23 and comprising raising a temperature of said growth element to a temperature which causes sterilization thereof. 28. A method according to claim 23 and comprising raising a temperature of said growth element to a temperature of approximately 70°C for a duration of approximately at least 3 hours. 29. A method according to claim 23 and comprising raising a temperature of said growth element to a temperature of approximately 60°C for a duration of approximately at least 4 hours. 30. A method according to claim 23 and comprising raising a temperature of said growth element to a temperature of approximately 100°C for a duration of approximately at least 3 hours. 31. A method according to claim 23 and comprising disinfecting said growth element approximately one day to two weeks before planting. 32. A method according to claim 23 and comprising growing a plant on a vertical side of one of said growth elements.

Inventors: HAZAN ELI, HAZAN, ELI
Applicants: HAZAN ELI, HAZAN, ELI
Application year: 1998
Main classification: A01G
IPC codes: A01G9