Abstract:
A system of irrigating a plurality of plants may include: a floor having an upper surface generally declining from an upper area location to a lower area location; an water delivery system for delivering an amount of water to the floor proximate the upper area location; and a drainage system for draining an excess portion of the amount of water from the floor. The system is operable to deliver water proximate the upper area location such that said amount water will flow toward the lower area location over the floor whereby a first portion of the amount of water flowing toward the lower area location will irrigate the plants. The system is also operable to drain an excess portion of the amount of water from the floor.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to floor irrigation systems. 
       BACKGROUND 
       [0002]    It is well known to irrigate plants including trees, bushes, flowers, algae (hereinafter referred to as “Plants”) in large scale growing operations. For example, irrigation systems are employed in large fields, vineyards, orchards and the like to provide water, and other nutrients, to Plants. In this document, the term “water” is used to include water, water in combination with one or more nutrients, a nutrient solution, or other fluid which it is desired to provide to Plants. 
         [0003]    For many years top irrigation of Plants was employed. However this general category of irrigation has significant drawbacks including being relatively high in labor intensity and inconsistent and unreliable amounts of irrigation of Plants. 
         [0004]    More recently the concept of sub-irrigation has been employed where Plants are irrigated from a water source located at a lower level and where the water may be introduced at the lower part, including the roots, of the Plants. 
         [0005]    Several distinct types of sub-irrigation systems are known including the watering matt, ebb and flow, trough benches and flood floors (e.g. concrete floors). Each type of sub-irrigation system has its own advantages and disadvantages. 
         [0006]    Flood floors, including in particular concrete flood floors, have become popular in large scale growing operations, particularly where a single Plants is being produced. The flood floors are often found in greenhouse locations where a protective transparent (e.g. glass) cover is provided over the floor. In known flood floors, typically a reinforced concrete floor is provided. The floor may consist of one or more continuous slabs of concrete which are supported on the ground/terrain by a suitable substrate (such as sand/gravel). The floor may have certain area locations that are positioned lower than other area locations. Sometimes, the floor will be sloped from one location to another location. 
         [0007]    However in the known types of flood floors, the water is both introduced and drained in the vicinity of the same lower location(s) on the floor. Water is introduced at one or more relatively low locations and gradually the water level rises to introduce water to the higher locations on the floor. Thus, as the term implies, the floor is flooded as the water level gradually rises to cover the floor. Generally, during the introduction of the water onto the floor, the water does not have a significant flowing movement on the floor. 
         [0008]    Once the Plants have been exposed to water for a period of time, no more water is introduced and the water that remains on the floor is drained. The water will first recede from the higher locations and then from the lowest locations as the flooded floor is drained. 
         [0009]    It will be appreciated that this type of flood floor system will result in uneven amounts of irrigation. The Plants that is located at the higher locations on the floor will be subjected to less irrigation than the Plants located in the lower locations on the floor. This is undesirable. 
         [0010]    In known flood floor irrigation systems, at least some of the same piping system that is used to deliver the water to the floor is also used to drain the excess water that has not been absorbed by the plants or evaporated. The excess water may well carry organic material, which can promote the growth of pathogenic organisms. Additionally, the excess water itself may hold pathogenic organisms. Thus, the excess water may result in the common piping becoming infected with pathogenic organisms. The result can be, that when water is fed onto the floor, the pathogenic organisms can be spread to many of the plants growing on the floor. 
         [0011]    Accordingly, an improved floor irrigation system is desirable. 
       SUMMARY 
       [0012]    In accordance with an aspect of the present invention there is provided a method of irrigating a plurality of Plants located on a floor, the floor generally sloping from an upper area location to a lower area location, the method comprising: delivering an amount of water proximate the upper area location of the floor; allowing the amount of water delivered at the upper area location to flow past the Plants to the lower area location over the floor whereby a first portion of the amount of water will irrigate the Plants; and draining an excess portion of the amount of water from the floor proximate the lower location. 
         [0013]    In accordance with another aspect of the present invention there is provided a method of irrigating a plurality of Plants located on a floor, the method comprising: introducing an amount of water on the floor and causing the amount of water to flow past the Plants whereby a first portion of the amount of water will irrigate the Plants; and draining an excess portion of the amount of water from the floor. 
         [0014]    In accordance with a further aspect of the present invention there is provided a system of irrigating a plurality of Plants comprising: a floor having an upper surface generally declining from an upper area location to a lower area location; an water delivery system for delivering an amount of water to the floor proximate the upper area location; and a drainage system for draining an excess portion of the amount of water from the floor, the system operable to deliver water proximate the upper area location such that the amount water will flow toward the lower area location over the floor whereby a first portion of the amount of water flowing toward the lower area location will irrigate the Plants, the system also being operable to drain an excess portion of the amount of water from the floor. 
         [0015]    Other aspects and features of the present invention will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    In figures which illustrate by way of example only, embodiments of this invention: 
           [0017]      FIG. 1  is a top, perspective view of a floor irrigation system; 
           [0018]      FIG. 1A  is an enlarged view at  1 A in  FIG. 1 ; 
           [0019]      FIG. 1B  is an enlarged view at  1 B in  FIG. 1 ; 
           [0020]      FIG. 2  is a top perspective view of the floor irrigation system of  FIG. 1 , with portions deleted so as to illustrate the piping system in more detail; 
           [0021]      FIG. 3  is a top plan view of a part marked  3  in  FIG. 1  of the floor irrigation system therein; and 
           [0022]      FIGS. 4A-E  are sectional views at section  4 - 4  in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    With reference to  FIG. 1 , one example embodiment of a Plants irrigation system  10  is illustrated. System  10  may have a greenhouse generally designated  12 , a piping system generally designated  14  and a water pumping and treatment station  16 . 
         [0024]    Greenhouse  12  may have a floor  18  over which a superstructure  20  may be located. Floor  18  may be made from any suitable material including but not limited to concrete, which may be reinforced in known ways such as for example using steel bar reinforcement (commonly known as “rebar”). As will be further evident hereinafter, floor  18  may have one or more sections. Each section may have an upper surface which slopes from one or more generally higher locations to one or more generally lower locations. 
         [0025]    As illustrated in  FIG. 1 , floor  18  can be divided into one or more floor sections such as sections  180  and  280 . Floor section  180  may have two slabs  181  and  182  oriented in a generally V-shaped valley configuration about a common axis X 1 . Water on the upper surface of slabs  181 ,  182  may flow in the direction shown by arrows  181   a,    182   a  toward the bottom of the valley proximate axis X 1 . 
         [0026]    Likewise floor section  280  may have two slabs  281  and  282  oriented in a generally V-shaped valley configuration about common axis X 2 . Water on the upper surface of slabs  281 ,  282  may flow in the direction shown by arrows  281   a,    282   a  toward the bottom of the valley proximate axis X 2 . 
         [0027]    The slabs  181 ,  182  can be configured such that the upper surfaces are oriented generally horizontal in the longitudinal direction of axis X 1 . Likewise, slabs  281 ,  282  can be configured such that the upper surfaces are oriented generally horizontal in the longitudinal direction of axis X 2 . In other embodiments, the upper surfaces of the slabs may not be oriented horizontally in the longitudinal direction. For example, the axes X 1  and X 2  may be sloped in one direction or another or opposite directions. 
         [0028]    In other embodiments, the upper surface of the floor  18  may be configured in other ways providing generally some kind of slope or decline from one or more generally higher locations to one or more generally lower locations. 
         [0029]    Each floor section can be made of any suitable material that fulfills the design characteristics required of the system  10 . The term floor as used herein is to be interpreted broadly and refers to any non-natural prepared surface supported proximate or on the underlying terrain and will include a material such as by way of example only a layer of concrete resting directly on the terrain. 
         [0030]    Each floor slab section  181 ,  182 ,  281 ,  282  may be made from concrete using standard construction techniques and of any suitable depth. By way of example, each slab may be in the range of about 2 inches to about inches in depth, and may in some embodiments be chosen to be about 4 inches in depth. The concrete can be reinforced with steel reinforcement members, using processes and materials that are well known. 
         [0031]    The floor slabs can be appropriately designed to withstand the necessary design loads including the loads that are associated with, for example, the Plants itself placed on the slabs, storage and person loads, vehicle loads, and other design loads. 
         [0032]    Additionally, expansion joints can be provided within and between each slab section to allow for expansion and contraction of the slabs due to changes in temperature of the concrete slabs. The expansion joints may be configured so that they do not unduly interfere with the flow of the water over the upper surface of the floor slabs, as hereinafter described in more detail. 
         [0033]    A sloped floor section can also be formed in known ways by, for example, preparing a sloped floor on grade, wherein a substrate supports the concrete slab. The sloped substrate may be formed in part from compacted foundation soil, gravel and/or sand. The uncured concrete may be poured onto the upper surface of the substrate and then finished in known ways to ensure an appropriate finish on the upper surface. 
         [0034]    The finish of the upper surface of the concrete may be made sufficiently flat (i.e. so that the surface lies close to one or more planar surfaces). The surface may also be finished to be suitably smooth (i.e. low roughness) so that water moving over it may generally remain laminar with little turbulence. Deviations from a smooth surface of greater than about 1 mm to 4 mm may be avoided. This finish may be achieved with a smooth trowel finish. 
         [0035]    In some example embodiments, average flow rates over the upper surface of the floor slabs may be in the range of about 0.5 to about 3.0 ft/sec. and may have an average depth in the range of about 0.1 inches to about 2.0 inches. The flow may be substantially laminar but may also some embodiments be turbulent. 
         [0036]    Returning to the example embodiment illustrated in  FIGS. 1 and 2 , the slope of the upper surfaces of slabs  181  and  182  towards the bottom of the V shaped valley and axis X 1 , may be in range of about 0.01 percent to about 2.0 percent, and may for example be about 1%. Likewise, the slope of the upper surfaces of slabs  281  and  282  toward the bottom of the v-shaped valley and axis X 2 , may also be in range of about 0.01 percent to about 2.0 percent, and may for example be about 1%. However, the slopes may in some embodiments possibly be less or more than this range, so long as the water will flow from one or more upper area locations to one or more lower area locations. For example slopes may be provided up to a 5% gradient. In some embodiments, these slopes may be provided in the longitudinal and/or lateral directions. 
         [0037]    It is not necessary that the amount of the slopes of any of the slabs  181 ,  182 ,  281 ,  282  be the same or substantially the same. Also, the degree of slope may not be constant across the surface in either the transverse or longitudinal directions. 
         [0038]    Positioned on floor sections  180  and  280  (only shown on part of section  280 ) are Plants  22 , which may be any suitable crop or the like which it is desired to cultivate. The Plants may be held in pots or other containers  150  (see  FIG. 4 ), with a growing medium, which may be soil or other known media, to hold the Plants therein and provide nutrients to the Plants. The containers  150  may be provided with openings suitable for allowing water that reaches the openings to penetrate inside the containers and be absorbed by the soil etc and thus provide a sustained source of water for the Plants. 
         [0039]    In some embodiments, a container to hold the Plants may not be required and the Plants may be self-supporting and rest directly on the floor slab surface, or employ a self-supporting growing media, which rest on the floor and support the Plants. 
         [0040]    Superstructure  20  may be provided for certain embodiments and may be any type of suitable kind, such as aluminum framing which is adapted to hold and support panels of transparent materials such as glass or some plastics. The framing of superstructure  20  can be supported on posts  41 . Superstructure  20  can provide protection from the external environment, which is particularly important in certain climates. 
         [0041]    Piping system  14  may include a water supply piping sub-system  24  and a water drainage sub-system  44 . 
         [0042]    With reference to both  FIGS. 1 and 2 , water supply piping sub-system  24  includes a main water supply pipe  28 , which may be connected at an input end  21  to a water source which is provided at station  16 . The water source communicates water under pressure to the main water supply pipe  28 . Pipe  28  may be any suitable pipe such as 6-inch interior diameter pipe made from PVC or other suitable material. 
         [0043]    Pipe  28  may communicate pressurized water to a T-junction  29 , where water may then be communicated to one or more water supply sub-pipes or sub-lines such as sub-lines  30   a  and  30   b,  which may pass under the floor slabs of floor sections  180  and  280 . Sub-lines  30   a  and  30   b  may be any suitable pipe or conduit such as 6 inch interior diameter pipe made from PVC or other suitable material. 
         [0044]    Sub-lines  30   a,    30   b  may run in generally spaced parallel relation to each other, generally transverse to the floor slabs of sections  180  and  280 , and may be generally orthogonal to longitudinal axes X 1  and X 2 . Sub-lines  30   a,    30   b  supply pressurized water to a plurality of water distribution pipes  32   a - 32   f  each of which may run generally longitudinally. At least one water distribution pipe is in some way associated with each of the floor slabs of sections  180  and  280 . 
         [0045]    In the vicinity of, and beneath, the first peak of the V-shaped floor section  180 , a water supply distribution pipe  32   b  may pass by and may cross (either under or over) sub-lines  30   a  and  30   b.  As illustrated, distribution pipe  32   b  may be divided into one or more separate sections such as section  132   b  and  232   b.  Distribution pipe  32   b  may lie within the substrate material and run in a generally longitudinal direction (generally parallel to axes X 1 ) and generally orthogonal to sub-lines  30   a  and  30   b.  Thus, distribution pipe  32   b  may generally run in the vicinity of the first peak of the V-shaped valley of section  180 . 
         [0046]    In the vicinity of and beneath the opposite, second peak of the V-shaped floor section  180 , a water supply distribution pipe  32   c  may also pass by and may cross over or under sub-lines  30   a  and  30   b.  Distribution pipe  32   c  may also lie in the substrate material and run in a generally longitudinal direction (generally parallel to axes X 1 ) and generally orthogonal to sub-lines  30   a  and  30   b.  Thus distribution pipe  32   c  may generally run in the vicinity of the second peak of the v-shaped valley of section  180 . 
         [0047]    Distribution pipes  32   b  and  32   c  may be interconnected to sub-lines  30   a  and  30   b  through separate pipe and valve mechanisms, one of which is shown in more detail in  FIG. 1A . Section  132   b  of pipe  32   b  and section  132   c  of pipe  32   c,  may be supplied with water from sub-line  30   b.  Likewise section  232   b  of pipe  32   b  and section  232   c  of pipe  32   c  may be supplied with water from sub-line  30   a.    
         [0048]    The water supply piping of section  280  may be substantially the same as section  180 . In the vicinity of, and beneath the first peak of the V-shaped valley floor section  280 , a water supply distribution pipe  32   d  may pass by and may cross (either under or over) sub-lines  30   a  and  30   b.  Distribution pipe  32   d  may run in a generally longitudinal direction (generally parallel to axis X 2 ) and generally orthogonal to sub-lines  30   a  and  30   b.  Thus, distribution pipe  32   d  may generally run in the vicinity of the first peak of the v-shaped valley section  280  (which may also be in the vicinity of or correspond with the second peak of section  180 ). 
         [0049]    In the vicinity of the opposite, second peak of the V-shaped valley floor section  280 , a water supply distribution pipe  32   e  may also pass by and may cross over sub-lines  30   a  and  30   b.  Distribution pipe  32   e  may also run in a generally longitudinal direction (generally parallel to axes X 2 ) and generally orthogonal to sub-lines  30   a  and  30   b.  Thus, distribution pipe  32   e  may generally run in the vicinity of the second peak of the v-shaped valley section  280 . 
         [0050]    Water distribution pipes  32   d  and  32   e  may also be interconnected to sub-lines  30   a  and  30   b  through separate pipe and valve mechanisms, an example of which is shown in more detail in  FIG. 1A . Section  132   d  of pipe  32   d  and section  132   e  of pipe  32   e,  may be supplied with water from sub-line  30   b.  Likewise section  232   d  of pipe  32   d  and section  232   e  of pipe  32   e  may be supplied with water from sub-line  30   a.    
         [0051]      FIGS. 1 and 2  also show water distribution lines  32   a  and  32   f.  These additional water distribution lines could be employed in additional floor sections for system  10 , which for simplicity are not shown. 
         [0052]    Each of water distribution lines  32   a - f  has in their upper surfaces a plurality of openings  33 , which are in communication with passageways that pass upwards through the slabs of the floor. The passageways may be configured not to unduly restrict the flow of water to the upper surface of the floor slabs. Thus, water emitted under pressure through the upper openings  33  in pipes  32   a - f  will pass through the slab and be communicated onto the upper surfaces of the floor slabs. 
         [0053]    The size and spacing of the openings  33  and the passageways through the slab can be selected to achieve the desired amount and type of water flow at the upper surface of each slab. For example, approximately 1 inch diameter holes can be provided at approximately 24 inches center to center spacing to supply approximately 10 US gallons per minute through each hole. The result can be that the water can exit the passageways in the slabs at a flow rate that substantially maintains a flow of water that runs along the upper surface of the concrete and avoids a turbulent or even geyser-like flow at the upper surface. 
         [0054]    The water delivered through openings  33  can be selected to provide a suitable flow of water on the upper surfaces of the slabs  181 ,  182 ,  281 ,  282 . The water flowing out of the openings  33  can be configured in some embodiments so that water will substantially flow down the slope in a cascading sheet of water having an average depth in the range of about 0.25 to about 2.0 inches. In some embodiments the average depth of the water that flows on the upper surface may be about 0.375 inches. 
         [0055]    By providing that each of supply distribution pipes  32   a - f  is divided into separate sections, such as for example  132   a - f  and  232   a - f,  it is possible to achieve a more even flow of water over the upper surface of the slabs. Each of water supply lines  30   a,    30   b  may supply substantially the same amount of water and be introduced at a location that divides the pipe lengths  32   a - f.  Additionally each section may be divided into approximately equal longitudinal lengths and the lengths may be configured to be not so long that there is a significant pressure drop longitudinally in each pipe  30   a - f.    
         [0056]    Additionally, by dividing the water distribution system into separate sections, it is possible that only selected longitudinal sections of the floor might be irrigated during particular time periods (i.e. It is not necessary to have to provide water over the entire surface of the floor  18 . 
         [0057]    As shown in  FIGS. 1 and 2 , the distribution pipes  32   a - f  may be beneath the section floor slabs  181 ,  182  and  281 ,  282 . The pipes  32   a - f  may have openings  33  in communication with passageways through the slab thickness, to provide water that emanates from beneath the upper surfaces of the slabs onto the upper surface. In other example embodiments, the distribution pipes may be situated with openings substantially at or a certain distance above the upper surface of the floor slabs  181 ,  182  and  281 ,  282 . However, the design may be selected so that the water which reaches the upper surfaces of the slabs creates a generally laminar flow of water down the slope. 
         [0058]    With reference now to  FIG. 1A , an example of an inter-connection system generally designated  80  is shown which can interconnect a representative water supply sub-line  30   a  with each of water distribution pipe sections  132   a  and  132   b.  Interconnection system  80  may include a T-connector  88 , which may connect a first end of a standpipe section  90  with sub-line  30   a.  The second, opposite end of standpipe section  90  may be interconnected to a second T-connector  86 , which may have two outlets  89   a,    89   b.  Outlet  89   a  may be connected to an inlet of a valve  82   a.  The outlet of the valve  82   a  may be connected to one end of a pipe section  92   a,  which at the opposite end may be connected to distribution section  132   a.  Outlet  89   b  may be connected to an inlet of a valve  82   b.  The outlet of the valve  82   b  may be connected to the end of a pipe section  92   b,  which at the opposite end may be connected to distribution section  132   b.    
         [0059]    Valves  82   a,    82   b  may be any suitable valve devices, such as for example a direct lift valve or solenoid valve. An example of a suitable valve is a plunger valve made by Zwart Systems. The valves  82   a    82   b  can be controlled electronically by a Programmable Logic Controller or suitable computer device  200  such at the environmental computers made by Priva Computers Inc. and Argus Control Systems Limited. Computer  200  can be employed to operate and control many or all aspects of the operation of system  10 , including the temperature in the superstructure, and the irrigation of the Plants as described below in further detail. 
         [0060]    All of the water supply sub-lines may be similarly interconnected with each of the water distribution pipe sections. 
         [0061]    System  10  may also include a water drainage piping system  44  that includes a main drainage pipe  27 . The main drainage pipe  27  may be connected at an outlet end  80  to a water storage and treatment system at the water pump and treatment station  16 . Pipe  27  may be any suitable pipe such as 6 inch interior diameter pipe made from PVC or any other suitable material. Pipe  27  may receive excess or run-off water from longitudinally oriented drainage water receiving pipes  36   a  and  36   b.  Pipe  27  may be sloped for gravity feed of the water towards station  16 . In some embodiments, drainage system  44  including main drain pipe  27 , may be selected to accommodate about 90% of the amount of water supplied to floor  18  by the water supply piping system  24 . Drainage system  44  can be as a whole adequately sized to ensure the continuous drainage of all excess water and thus avoid any “back-ups.” 
         [0062]    The main drainage pipe  27  can be interconnected to each of pipes  36   a,    36   b  at a medial location of the pipes through a T-junction connection  39 . Each of receiving drainage pipes  36   a  and  36   b  may be located so as to pass under the upper surface of floor slabs of floor sections  180  and  181 , and indeed may be under each of the entire slab of each section and run in the substrate. Receiving drainage pipes  36   a  and  30   b  may run in generally spaced parallel relation and generally parallel to their respective axis X 1  and X 2  and slope longitudinally from opposite ends towards medial locations at the T-junction connection  39 . Accordingly, water in pipe  36   a  may generally run beneath and in the vicinity of the trough of the upper surface of v-shaped valley section  180 . Likewise pipe  36   b  may run generally beneath and in the vicinity of the trough of the upper surface of v-shaped valley section  280 . Also, water in pipes  36   a  and  36   b  may run into and be communicated into main drainage pipe  27 . 
         [0063]    Openings  133  may be provided at spaced intervals along the top of pipes  36   a,    36   b  and may be in communication with openings or passageways thorough the floor slabs. Therefore, water that drains into the bottom of the V-shaped valley sections  180 ,  280  may pass through the upper surface of the floor slabs and pass into the pipes  36   a,    36   b.  The size of the openings  133  and corresponding passageways through the slabs may be chosen to ensure appropriate draining of the excess water. The selection may be done to ensure that there is substantially little or no water build up in the bottom of the valley sections (i.e. substantially no flooding takes place). For example, openings  133  may be provided with accompanying passageways through the slabs that are 2 inches in diameter at 12-inch center to center spacing. 
         [0064]    A barrier device (not shown) may be provided to run longitudinally at the bottom of the v-shaped valley of sections  180  and  181 . The barrier device may pass over and link each of openings  133 . The purpose of the barrier device is to inhibit water flowing down the slope of the section slabs on one side of the v-shaped valley section, running past the openings  133  and start to climb the opposite side slab. By providing the barrier, the plants near the vicinity of the bottom of the valley proximate the openings  133 , will not be subjected to additional amounts of water due to a spillover effect. The barrier device can be any suitable device such as a flexible rubber dam device that is commercially available. 
         [0065]    With reference now to  FIG. 1B , additional drain tubes or pipes (which may be for example 16 mm tubes  152  made from any suitable material including polyethylene), may be provided. Tubes  152  provide fluid communication between pipe sections  32   a,    132   a,    32   b  and  132   b  (not shown) and drainage pipe  27 . Drain tubes  152  assist in reducing the build up of any significant amounts of stagnant water in these pipe sections. Tubes  152  may be provided with separate valves (not shown) which can be closed during the irrigation of the Plants when water is fed to the water distribution pipes. Alternatively, since tubes may be narrow in internal diameter, the tube passageway may remain open during the irrigation cycle but little of the overall supply of water will pass through tubes  152 . 
         [0066]    Returning again to  FIGS. 1 and 2 , station  16  may provide for system  10  a water storage, treatment and pumping capability and complete the fluid flow circuit. Additionally water that is lost from the system either to evaporation or in the irrigation of the Plants, can be replaced from an external water source such as the main municipal water system. 
         [0067]    Water tanks  35  may be used to hold the water that is used in the system and may comprise a tank  35   a  and tank  35   b.  Water held in tank  35   a  may be subjected to known types of water treatment processes which include for example filtration and Ultra violet treatment. The treated water is then passed to storage tank  35   b  where it is held. Water can be drawn from tank  35   b  on demand by a pump  45  and the passed under pressure to main supply line  28 . Pump  45  may be any suitable pump which has the performance characteristics required for the system  10  and may for example be a model WS 5032 pump made by Gould. 
         [0068]    Additionally, environmental computer  200  may be housed at station  16  and can be used to operate and control various aspects of the system  10  including the operation of the pump  45 , the valves  82   a,    82   b  and various aspects of the water treatment. Computer  200  can be interconnected with various types of sensors located in the vicinity of the Plants. These sensors can for example measure the ambient humidity and temperature. Additionally moisture level sensors might be provided to detect the moisture in, for example, the growing medium, or of the one or more Plants. Upon receipt of appropriate signals from sensors or otherwise the computer  200  can be programmed to provide for irrigation of the Plants in any particular section of the floor  18 . Slab sections can be selectively irrigated at different times and/or different lengths of time, depending upon the desired irrigation. In this way, for example, different types of Plants may be irrigated on different sections of the floor  18 , for different periods of time and at different times. 
         [0069]    Of course, aspects of the system  10  may be controlled additionally or alternatively by manual intervention. 
         [0070]    With reference now to FIGS.  3  and  4 A-E, the operation of the system  10  in performing an irrigation cycle for floor sections  281 ,  282  is illustrated. 
         [0071]    As shown progressively in  FIGS. 4A-E , the water may be first supplied to the upper surfaces of floor slab sections  281 ,  282  through supply system  24  as described above, as shown in  FIG. 4A . This may be effected by computer  200  turning on the pump  45  and opening the appropriate valves  82   a,    82   b.  The result is that sheets of water  100 ,  101  may then start to flow from distribution pipe sections  232   d,    232   e  down the upper surface of the slabs  281  and  282 , respectively. The water may establish a fairly uniform and laminar flow as water starts to flow as shown in  FIG. 4B . This process continues until an equilibrium flow regime as illustrated in  FIG. 4C  is established in which a continuous flow of water may be established between the distribution pipe sections  232   d,    232   e  and the common drain pipe section  36   a.    
         [0072]    The flow regime established in  FIG. 4C  can be maintained for any period of time that it is desired to provide appropriate irrigation of the Plants. For example, this water flow may be maintained for a period of time in the range of about 30 seconds to about 20 minutes. 
         [0073]    When water flows past the pots or other containers in which the Plants are held, a portion of that water will enter through openings in the pots and be absorbed therein. 
         [0074]    After the Plants have been irrigated sufficiently, the water supply will be terminated and no additional water will emanate from the water distribution pipe sections  232   d  and  232   e.  Thus the terminal end of the sheets of water  100 ,  101  will gradually move down the slope as shown in  FIGS. 4D and 4E . 
         [0075]    The foregoing description of water flow across the floor surface can occur on any or all of the slab sections  181 ,  182  and  281 ,  282  (or parts thereof) to the extent to which water is supplied to and emanates from one or more of water distribution pipe sections  132   b - e  and  232   b - e.    
         [0076]    In other embodiments, the continuous sheet of water shown in  FIG. 4C  may never be established in an irrigation cycle. A sheet of water having a front end and a rear end may simply be generated which then passes down the slope. 
         [0077]    The irrigation cycles can be varied and can be repeated as required in the particular application. 
         [0078]    In this document the use of the term “including” means “including without limitation” and is not to be construed to limit any general statement which it follows to the specific or similar items or matters immediately following it. 
         [0079]    The foregoing relates to only exemplary embodiments of the invention, it being understood that numerous other modifications, variants, embodiments and changes are possible within the scope and spirit of the invention.