Abstract:
A method and system for continuous automated growing of plants utilizes production lines each comprising a number of growth sections, each growth section comprising multiple horizontal transport levels, each level of each section having a source of light and liquid nutrient, and plant growing trays which move horizontally into, along and out of each transport level; whereby each subsequent growth section has a greater length than the previous section to receive a greater number of growing trays than the previous section so that as plants grow, the number of plants per growing tray is decreased but the number of plants per growth section remains constant. A group of plants is thereby broken out into an ever greater number of trays as it proceeds through the growing sections from germination to harvest, with the ability to simultaneously start the growth cycle for additional crops.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims the benefits, under 35 U.S.C. §119(e), of U.S. Provisional Application Ser. No. 61/592,338 filed Jan. 30, 2012 entitled “Method and Apparatus for Automated Horticulture and Agriculture” which is incorporated herein by this reference 
    
    
     TECHNICAL FIELD 
     The invention relates to the fields of horticulture and agriculture and particularly apparatus and methods for automated commercial growth and production of plants in controlled environments. 
     BACKGROUND 
     Traditionally the commercial horticultural and agricultural growth of plants has been carried out in nurseries and greenhouses, where the plants are arranged horizontally and are stationary. More efficient methods have more recently been developed, some of which are referred to as ‘vertical farming’. The present inventor, for example, in U.S. Pat. Nos. 7,415,796, 7,533,494, 7,559,173, 7,818,917 and 7,984,586 disclosed methods of growing plants using a rotating vertical carousel of rotating spheres, each having a central light source around which rows of plants are rotated, to thereby increase the productivity of plant growth in a given area. However harvesting of mature plants from such systems can be complicated and time consuming. 
     The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings. 
     SUMMARY 
     The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements. 
     The present invention provides a method and system for continuous automated growing of plants. The method utilizes one or more production lines each comprising a first and subsequent growth sections, each growth section comprising a plurality of horizontal transport levels, each level of each section having a source of light and liquid nutrient, and a plurality of growing trays which are adapted to move horizontally into, along and out of each one of said transport levels; whereby each subsequent growth section has a greater length than the previous section to thereby receive a greater number of growing trays than the previous section so that as plants grow in the growing trays, the number of plants per growing tray is decreased but the number of plants per growth section remains generally constant, the method comprising: 
     i) planting a first group of said growing trays with seeds, the number of seeds planted in each tray being selected according to the type of plant, the size of trays, and the relative number and lengths of said growing sections; 
     ii) introducing said first group of seeded trays into the first growing section; 
     iii) after a sufficient germination period, transplanting the first group of plants from the first group of trays into a greater number of trays able to be received in the next subsequent growing section; 
     iv) introducing the trays containing the first group of plants into the first subsequent growing section; 
     v) introducing a second group of seeded trays into the first growing section; 
     vi) after the first group of plants have grown for a sufficient period of time in said first subsequent section, transferring the first group of plants again into a greater number of trays able to be received in the next subsequent growing section; 
     vii) introducing the trays containing the first group of plants into the next subsequent growing section; 
     viii) transplanting the second group of plants from the second group of trays into a greater number of trays able to be received in the next subsequent growing section; 
     ix) introducing the trays containing the second group of plants into the next subsequent growing section; 
     x) repeating steps i) through ix) mutatis mutandis for the first, second and subsequent groups of plants from the first, second and subsequent groups of seeded trays; 
     xi) once the plants in a group of trays are in the final subsequent growth section and are ready to harvest, removing the group of trays from the final growth section and harvesting said plants. 
     According to one aspect of the invention each growing section comprises multi-level growing units, each independently controlled for light cycle and feeding and irrigation cycle and which may be computer operated so that the system can be programmed for different plants having differing growth cycles, without any changes to the configuration of the installation. The invention further provides a system constructed to carry out the foregoing method and a growing tray specially designed for horizontal movement on rollers within the multi-level growing units. The growing tray has an automatic filling and draining cycle which is regulated by a novel form of bell siphon. The bell siphon uses a baffle having passages of variable diameter situated between the stand-up pipe and the bell so that the degree of vacuum can be selected and the timing of the fill and drain cycle selected as necessary. 
     In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive. 
         FIG. 1  is a perspective view of an installation for carrying out the method of the invention; 
         FIG. 2  is a perspective view of a single production line of the installation shown in  FIG. 1 ; 
         FIG. 3  is a front right perspective view of a single unit of a production line of the installation shown in  FIG. 2 ; 
         FIG. 4  is a left rear perspective view of a single unit of a production line of the installation shown in  FIG. 2 ; 
         FIG. 5  is a detail of the perspective view shown in  FIG. 4 ; 
         FIG. 6  is a detail of the perspective view shown in  FIG. 3 ; 
         FIG. 7  is a further detail of the perspective view shown in  FIG. 4 ; 
         FIG. 8  is a perspective view of a cleaning area of the installation shown in  FIG. 1 ; 
         FIG. 9  is a top view of a germination tray with 16 seed flats; 
         FIG. 10  is a perspective view of the germination tray shown in  FIG. 9 ; 
         FIG. 11  is a top view of a tray for the second stage with 165 pots; 
         FIG. 12  is a perspective view of the tray shown in  FIG. 11 ; 
         FIG. 13  is a top view of a tray for the third stage with 54 pots; 
         FIG. 14  is a perspective view of the tray shown in  FIG. 13 ; 
         FIG. 15  is a perspective view of the bell siphon used to regulate drainage from the trays, with the outer housing in phantom outline for purposes of illustration; 
         FIG. 16  is an exploded perspective view of a variant of the bell siphon shown in  FIG. 15  with the outer housing in phantom outline for purposes of illustration; 
         FIG. 17  is a perspective view of the restrictor part of the bell siphon shown in  FIG. 16 ; and 
         FIG. 18  is a cross-section of the restrictor shown in  FIG. 17  taken along lines A-A. 
     
    
    
     DESCRIPTION 
     Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense. 
     With reference to  FIG. 1 , an installation for automated cultivation and harvesting of plants is designated generally as  10 , installed in a large building  12  such as a warehouse. The installation  10  includes the growing and harvesting area  14 , cropping and packaging area  16 , cold storage  18 , cleaning area  20 , seeding area  21  and tank storage area  22 . The growing area comprises a plurality of production lines  24 , one of which is shown in  FIG. 2 . A conveyor  26  carries trays  80  from the production lines  24  through the cropping and packaging area  16  to the cleaning area  20 . 
     With reference to  FIG. 2 , each production line  24  comprises a germination section  28 , a second stage growth section  30  and a third stage growth section  32 . Preferably each production line  24  will have one germination section unit  44 , five second stage units  44  and fifteen third stage units  44 . Wheeled scissor lifts  34 ,  36  are provided between germination section  28  and second stage section  30 , and between second stage section  30  and third stage section  32  respectively. A third wheeled scissor lift  38  is provided to remove the finished product at the end of each production line  24 . Scissor lifts  34 ,  36  and  38  are motorized and move in the direction perpendicular to production lines along pathways  40 ,  42 ,  50  to permit the scissor lifts to service each production line  24 . 
       FIGS. 3-7  illustrate an individual unit  44  of a production line  24 . Each unit comprises a frame  46  forming a number of transport levels  48 . In the embodiment shown, there are 11 transport levels  48  but a larger or smaller number can be provided depending on the desired size of the operation. Each transport level comprises a plurality of parallel rollers  52  which are bearing mounted for rotation in transversely extending roller supports  54 . Rollers  52  support the plant trays  80 . Each transport level also has a drainage trough  58  which drains into vertical drainage pipes  60  through connecting tubes  62 . 
     On the underside of each transport level  48 , and on the underside of top level  61 , are arrays  64  of fluorescent lamps  66 , preferably 14 parallel 8 foot T8 High Output fluorescent lamps  66  per array  64 . Preferably three arrays  64  on adjacent levels are controlled by a single remotely controlled electrical switch  68  connected by conductors  70 . While fluorescent lamps are shown, other growth promoting lights can be used, such as light emitting diodes (LEDs), high pressure sodium lamps, metal halide lamps or incandescent light bulbs. The electrical switches  68  are programmed to provide a coordinated light cycle (photoperiod) for the plants at each growth stage and depending on the particular plant. 
     Liquid supply pipe  72  supplies liquid nutrient solution to the trays on each level through outlets  74 . Each outlet is controlled by solenoid valves  76 , which are electrically controlled by wireless controllers  78  to which they are connected by conductors  77 . Liquid nutrient is delivered to the liquid supply pipe  72  from feed tanks  73 ,  75 ,  77  for each of stages  32 ,  30 ,  28  respectively. The liquid nutrient solution is mixed in batch tanks  63 ,  65 ,  67  for each of stages  28 ,  30 ,  32  respectively. 
     Plant trays  80  are preferably molded plastic trays 4 feet wide by 8 feet long, with 6-inch high side walls  82 . Ramps  83  can be used to avoid splashing as the liquid flows to the bottom of the tray. The pattern of channels  84 ,  86  in the upper inner surface of the trays  80  causes the nutrient solution to be equally distributed throughout the tray until it flows out the drainage holes  88  at the end of tray  80  opposite from the outlets  74 . 
     To maintain the liquid in the trays at the proper level, prevent overflow and periodically drain trays  80 , preferably a bell siphon  89  is used in the drainage hole  88 , as illustrated in  FIGS. 15-18 . Bell siphon  89  comprises a stand-up pipe  100  having threaded ends  102 ,  104 , O-ring  106 , cylindrical enclosure  108 , bell  110 , annular collar  112  having holes  113  and retaining ring. O-ring  106  sits in groove  107 . Stand-up pipe  100  is screwed into the drainage hole  88  by threaded end  102 , with O-ring  106  thereby being compressed between stand-up pipe  100  and tray  80 . Drainage hole  88  is connected to drainage trough  58  which drains into vertical drainage pipes  60  through connecting tubes  62 . Stand-up pipe  100  has a lower central cylindrical passage  114  and an upper cylindrical passage  116  with a greater diameter than the lower section and joined by a shoulder  115  having a beveled angle M. Collar  112  threads onto threaded end  104  of stand-up pipe  100  and bears against shoulder  120  which is formed between the lower section  122  of bell  110  and the upper section  124  which has a smaller diameter. Bell siphon  89  operates in the usual way to prevent the tray from filling to a higher level than the height of stand-up pipe  100 , and periodically draining and refilling the tray by a siphon action. 
     Bell  110  is sized so that liquid from tray  80  is able to flow under the lower edge of bell  110  into the space between bell  110  and the stand-up pipe  100 . As the tray fills, liquid flows through holes  113  and into the stand-up pipe  100  to flow through drainage hole  88 . Thus collar  112  acts as a baffle to restrict the flow of liquid and by varying the number of holes  113  in collar  112  the length of time to fill the tray, and the length of time the tray will drain before the siphon is broken, can be varied. For example a collar with 6 holes of the same diameter as the 8-hole version shown can be substituted to cause the tray to fill and drain on a quicker schedule. 
       FIGS. 9 and 10  show the tray  80  loaded with flats  81  of seeded germination pucks  83  for placement in the first germination stage  28 .  FIGS. 11 and 12  illustrate the tray  80  after the flats  81  of seeded germination pucks from the first germination stage have been broken out into pots  85  for placement in the second growth stage  30 .  FIGS. 13 and 14  illustrate the tray  80  after the pots  85  from the second growth stage  30  have been thinned out for the third growth stage  32 . 
     In operation trays  80  are planted with seeds in the seeding area  21 . The number of seeds planted in each tray will depend on the type of plant, with the goal being that after the plants have been broken out into the third stage of growth, each tray  80  will be sufficiently filled with grown plants. In the example below, for example, to arrive at a finished crop of 55 lettuce heads per tray after the third growing stage  32 , for the germination stage each tray  80  will contain about 1680 germination pucks seeded with lettuce seeds. Once the trays  80  are loaded with the flats of seeded pucks they are transported to the germination section  28  on scissor lifts. 
     After a sufficient germination period, each tray of seedlings is broken out into the number of trays required to fill the second stage section at that transport level, which in the embodiment shown is 5. The breaking out onto additional trays and loading into the next section  30  is done manually on scissor lift  34 . Once the entire section  30  has been loaded the plants are permitted to grow for a sufficient period of time until it is necessary to break them out again into a greater number of trays, 15 in the embodiment shown. This is done manually on scissor lift  36 . Again the plants are left in section  32  until they are ready to harvest. Meanwhile sections  28  and  30  are filled and growing with a new crop. Once the plants in section  32  are sufficiently mature, the trays  80  are manually removed from each level onto scissor lift  38  and loaded onto conveyor  26 . The trays are then taken to the cropping and packaging section  16  where the plants are manually removed and packaged and stored in cold storage  18 . Trays  80  then move to the cleaning section  20  where they are cleaned using washer  90  and drier  92  and returned to the seeding section where they are refilled with seeds. 
     Example—Romaine Lettuce 
     An example of application of the invention to the production of Romaine lettuce is described as follows. The preferred liquid nutrient solution mixes are: 
     i) a Bacterial Compost Tea mixed by, for each 20 L of filtered water adding 
     1.5 pounds (700 g) bacterial compost or vermicompost 
     3-4 tablespoons (45-60 ml) liquid black strap molasses 
     4 teaspoons (23 g) dry soluble kelp or 2 tablespoons of liquid kelp 
     3-4 teaspoons (15-20 ml) fish emulsion 
     ii) as a fertilizer/nutrient solution, PURA VIDA™ GROW produced by Technaflora Plant Products of Mission BC, Canada. EDTA Iron is added at 20 ppm to the final solution. 1 gallon of compost tea is added for each 50 gallons of the feed solution with each new batch mixture. 
     In the Stage 1, the germination stage  28 , seeds are planted into Jiffy™ peat pucks  83  (preferably Item #70000591), which are seed starting plugs, 105 peat pucks per each germination flat  81  (see  FIG. 9 ). The seeded puck trays  81  are saturated in the bacteria-dominated compost tea solution at 5.8 pH. A humidity dome (not shown) is placed on top of each germination flat  81 . 16 germination flats  81  are placed in each tray  80  (see  FIG. 9 ) and the tray is then loaded onto each level  48  of unit  44  in the germination section  28 . Temperature is maintained at 69 degrees F. and humidity at 72%. For lighting, the light cycle (photoperiod) is set at 18 hours/On-6 hours/Off. During Days 1-4 the seeded flats are kept under humidity covers. On Day 5 the humidity covers are removed. On Day 7, the plants are sprayed with the full strength compost tea solution at 5.8 pH. For Days 7-15. the media is soaked once per day with a 400 ppm fertilizer solution at 5.8 pH. 
     At Day 15 the Plants are transplanted into molded plastic pots  85  filled with 75% Botanicare™ Cocogro® Coir Fiber media to 25% perlite. Botanicare ZHO™ Root Inoculant is added according to the label directions and also added is 1 tbsp dolomite lime per gallon of media saturated in the same compost tea mix used in the seeding process. Plants are spaced at 165 pots per growing tray  80  (See  FIG. 11, 12 ) and placed onto each level  48  of unit  44  in the second stage section  30 . For the second stage, the temperature is maintained at 62 degrees F., the humidity is maintained at 68% and the light cycle is kept at 18 hours On, 6 hours Off. At days 15-30, the grow trays  80  are flooded once a day with the fertilizer solution at 540 ppm at 5.8 pH. At Day 30, the media is saturated at 1 EC (electrical conductivity) and plants are sprayed with the full strength compost tea solution brewed as above at 5.8 pH. The Plants are then moved to the third stage section  32  and thinned to 55 plants (pots  85 ) per tray  80 . 
     In the third stage section  32 , the temperature is maintained at 62 degrees F., humidity is maintained at 68% and the light cycle is 18 hours On, 6 hours off. From Days 30-45, the trays  80  are flooded twice a day with the nutrient solution at 640 ppm at 5.8 pH. At Day 45 the Plants are harvested. 
     Thus using the invention, a continuous automated and controlled production of plants can be obtained. Different lighting, temperatures, humidity and nutrition can be programmed for the different growth stages of a crop and also for different crops. This can be done remotely by computer. Thus the installation can quickly change from producing one crop to another if demand for a crop and pricing are changing quickly. The land space required to produce a crop is dramatically reduced and can be further reduced by increasing the height of the growing units  44 . The entire process can be automated using robots to transfer the plants at different stages. 
     While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the invention be interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.