Patent Publication Number: US-2021185934-A1

Title: Methods and systems for measuring throughput in agricultural equipment

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 62/951,213, filed Dec. 20, 2019, which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     Field 
     Aspects of the invention are generally directed to agricultural equipment including agricultural balers and other crop-gathering equipment. More particularly, aspects of the invention are directed to agricultural balers or other equipment that provide throughput data or other agronomic information to an operator. 
     Description of Related Art 
     Producers often use an agricultural baler to collect crop materials such as hay or similar from a windrow and compress the hay or other crop into a bale for easy transport and storage. For example, when the grass in a hay field is tall enough for baling, the grass is cut raked into a windrow (i.e., a long line of hay), allowed to dry in the sun and wind, and then processed in an agricultural baler being pulled by a tractor or similar tow vehicle. The agricultural baler picks up the cut hay, conveys it to an internal baling chamber, and compresses the hay into a desired bale shape. Most commonly, the agricultural baler will form the hay into a cylindrically shaped bale having a circular cross-section (i.e., a “round baler”), but other balers may form the hay into a rectangular prism shape having a square cross-section (i.e., a “square baler”). 
     Generally, on a round baler a spinning pickup header engages the cut material in the windrow and directs it to one or more rotors, augers, and other components of a feed mechanism that in turn conveys the cut grass or hay to a baling chamber. The baling chamber includes a series of compression belts that receive the hay and carries it into the baling chamber. The belts are generally upward and outward moving so that a circumference of a portion of the belts pressing on the outer surface of the bale increases as more hay is fed into the baling chamber until the bale reaches a desired size. Once the bale is full size, a wrapping system wraps the cylindrical bale in a suitable bale wrap such as a plastic sheet, net, or other bale wrap. A rear tailgate of baler opens and ejects the bale, and the process repeats itself for the next bale. A similar process is used to create a square bale, however, instead of the hay being conveyed into a chamber including ever-increasing circumferential belts, the hay may be forced into a chamber having a square cross-section and compacted therein and wrapped with twine to form the square bale. 
     When using an agricultural baler, the operator must continually change speeds to accommodate for the varying amounts of hay in the windrow or other operating conditions. If the operator moves too fast, the operator may overload the pickup headers or pressure-exerting belts resulting in a clog or unevenly distributed bale, while simultaneously increasing horsepower (and thus fuel) requirements. Conversely, if the operator travels too slow, efficiencies decrease. Because current balers are unable to provide an operator feedback regarding how much hay is being taken up by the pickup headers as the baler is pulled along the windrow, operators are unable to accurately and efficiently determine at what speed to operate a tractor or otherwise accurately and efficiently adjust operating parameters to achieve a desired baling performance. There thus remains a need for a baler that provides feedback to a user during operation such as a real-time indication of the rate of hay entering the baler. 
     BRIEF SUMMARY 
     The present invention is directed to methods and systems for collecting organic material throughput data by measuring data associated with a force acting on a floor of agricultural equipment. In some embodiments, the data is measured using at least one of a load cell, pressure sensor, and/or a displacement sensor. The data associated with the force acting on a floor of the agricultural equipment is correlated to a throughput of material being conveyed through the agricultural equipment, and provided to an operator or tow vehicle, in some embodiments in real time. 
     For example, some embodiments of the invention are directed to a method of monitoring a throughput of a crop in agricultural equipment. The method includes picking cut organic material out of a field using the agricultural equipment and conveying the cut organic material through a feed mechanism of the agricultural equipment, which may include a rotor and a floor proximate the rotor. The method further includes measuring, with a first sensor associated with the floor, force data during the conveying, the force data comprising at least one of: a force exerted on the floor, a pressure applied to the floor, and a displacement of the floor. The method also includes correlating the force data to a rate at which the cut organic material is conveyed through the feed mechanism. 
     In some embodiments, the method may further include measuring, with a second sensor associated with the rotor, speed data comprising a speed of the rotor during the conveying. In such embodiments both the force data and the speed data is correlated to the rate of the cut organic material being conveyed through the feed mechanism. 
     Other embodiments of the invention are directed to a system for monitoring a throughput of a crop in agricultural equipment. The system may include an agricultural baler comprising a crop pickup portion and a baling portion. The crop pickup portion includes at least one rotor and a floor proximate the rotor, with the crop pickup portion being configured to pick up cut organic material from a field and convey the cut organic material downstream to the baling portion. The baling portion is configured to receive the cut organic material being conveyed by the crop pickup portion and bale the cut organic material. The system may further include a material throughput sensing system, which includes a first sensor operatively coupled to the floor and configured to measure force data proportional to a force being exerted on the floor by the cut organic material conveyed by the crop pickup portion, the force data comprising at least one of: a force exerted on the floor by the cut organic material, a pressure applied to the floor by the cut organic material, and a displacement of the floor, and a second sensor operably coupled to the rotor and configured to measure speed data comprising a speed of the rotor as the cut organic material is conveyed by the crop pickup portion. The system may further include a processor configured to correlate the force data and the speed data to a rate of the cut organic material being conveyed through the crop pickup portion. 
     These and other features will be discussed in more detail below in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is described in detail below with reference to the attached drawing figures, wherein: 
         FIG. 1  is an elevation view of an agricultural baler as one example of agricultural equipment used to collect organic material throughput data according to aspects of the invention; 
         FIG. 2  is a perspective view of the agricultural baler shown in  FIG. 1  and showing a crop pickup portion according to aspects of the invention; 
         FIG. 3  is a fragmentary view of the agricultural baler shown in  FIGS. 1-2  and showing in detail the crop pickup portion according to aspects of the invention; 
         FIG. 4  is cross-sectional view of the agricultural baler shown in  FIGS. 1-3  and showing the crop pickup portion and a baling portion according to aspects of the invention; 
         FIG. 5  is an elevation view of certain components of the crop pickup portion of the agricultural baler shown in  FIGS. 1-4 ; 
         FIG. 6  is a schematic showing the operation of a material throughput sensing system of the agricultural baler shown in  FIGS. 1-5  according to aspects of the invention; 
         FIG. 7  is a flowchart schematically representing a method of adjusting an operating parameter of agricultural equipment using a material throughput sensing system, such as the one shown in  FIG. 6 , according to aspects of the invention; and 
         FIG. 8  is a flowchart schematically representing a method of making at least one planting or treatment decision using a material throughput sensing system, such as the one shown in  FIG. 6 , according to aspects of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Generally, aspects of the invention are directed to methods and systems for measuring a rate of hay or other crop take-up by a piece of agricultural equipment such as an agricultural baler. More particularly, in embodiments directed an agricultural baler, the methods and systems measure a rate of hay being taken in by the baler as a bale is being formed by correlating a force being exerted by the hay on a rotor floor in the crop pickup portion of the agricultural baler. This data in turn provides an operator real-time yield data and other valuable agronomic data and, in some embodiments, can be used to aid in autonomously controlling the speed of a tractor employing a Tractor Implement Management (TIM) system, among other benefits. These and other aspects of the invention will become more apparent via the detailed description of the invention in connection with the accompanying figures. 
       FIG. 1  shows an agricultural baler  10  that may employ various aspects of the invention. Although for simplicity aspects of the invention will be described in detail with respect to the agricultural baler  10 , the invention is not limited to the agricultural baler  10  and may be employed on various types of agricultural equipment without departing from the scope of the invention. For example, although the agricultural baler  10  is a round baler, in other embodiments aspects of the invention may be included on a square baler or other type of baler. Or aspects of the invention may be employed on non-baler equipment such as a combine harvester or the like with the material throughput sensing system described herein incorporated in a crop gathering header of the combine harvester. 
     The agricultural baler  10  generally includes a towing and driveline portion  12  extending from a main body  14 . The towing and driveline portion  12  includes a tow hitch  16  configured to be connected to a towing vehicle such as a tractor or the like during operation, such that the baler is pulled in a forward direction along a windrow of dried hay or similar crop lying in a field. The towing and driveline portion  12  may also include driveline connections  18  ( FIG. 4 ) for operably connecting the drivable features of the agricultural baler  10  (i.e., the pickups, rotor, baling mechanism, etc., which will be discussed in more detail below) to a power take-off (PTO) portion of the towing vehicle. 
     The main body  14  generally includes a crop pickup portion  20  and a baling portion  22 . During operation, the crop pickup portion  20  engages the cut hay or other crop lying in a field and conveys it upward and rearward towards the baling portion  22 . The baling portion  22  in turn compresses the hay into a desired shape (in the case of a round baler, into a cylindrical bale), wraps the bale, and ejects the bale into the field for later retrieval. 
       FIGS. 2 and 3  show the crop pickup portion  20  in more detail. The crop pickup portion  20  includes a rotary rake  24  that engages the hay or other crop in a windrow. The rotary rake  24  includes a plurality of spinning tines  26  that contact the hay or other crop as the agricultural baler  10  is towed forward and flings the hay or other crop upwards and rearwards toward the baling portion  22 . The crop pickup portion  20  may further include a rotor  28  that is configured to stuff the hay or other crop into the baling portion  22 . In some embodiments, the crop pickup portion  20  may include one or more augers operably coupled to the rotor  28  and sandwiching a plurality of stuffers  34  or else provided upstream of the rotor  28 . When the hay or other crop leaves the rotary rake  24 , the augers center the hay and the spinning stuffers  34  of the rotor  28  pack the hay into the baling portion  22 . 
       FIG. 4  shows the baling portion  22  in more detail. The baling portion  22  generally includes a baling chamber  36 , a plurality of compression belts  38 , and a wrapping mechanism. The rotor  28  stuffs the hay or other crop into the baling chamber  36 , and more particularly into the compression belts  38  provided in the baling chamber  36 . The rotating compression belts  38  continuously roll the hay or other crop and apply pressure thereto, therefore compacting the hay or other into a densely packed bale. The compression belts  38  are expandable such that as more and more hay or other crop enters the baling chamber  36 , the circumference of the portion of the belts  38  pressing on the bale  42  (shown in  FIG. 6 ) expands as the outer circumference of the bale  42  expands with the addition of more hay or other crop  55  being added to the bale  42 . Once the desired size of the bale  42  is achieved, the wrapping mechanism wraps the outer circumference of the bale  42  in plastic, netting, or another desired wrap. Finally, a movable tailgate  44  of the agricultural baler  10  swings open and the wrapped bale  42  is ejected into the field for later collection. 
     Some embodiments of the invention are directed to a material throughput sensing system incorporated into agricultural equipment such as the agricultural baler  10  shown in  FIGS. 1-4 , which senses a force exerted on portions of the crop pickup portion  20  and correlates the force to a rate of hay or other crop entering the baling portion  22  of the agricultural baler  10 . More particularly, in some embodiments the crop pickup portion  20  may include a movable rotor floor  46  directly beneath the rotor  28 , as shown in  FIGS. 5 and 6 . The movable rotor floor  46  may beneficially increase the cross-sectional area of an inlet to the baling chamber  36  in an effort prevent the inlet of the baling chamber  36  from becoming blocked. More particularly, the movable rotor floor  46  reduces the risk of blockage by incorporating a suspension unit that allows the rotor floor  46  to translate and/or rotate with respect to a rotational axis  29  of the rotor  28  thereby dynamically altering a passageway between the rotor  28  and the floor  46  during use. In some embodiments, for example, the suspension unit may include one or more suspension members  47 , which, in some embodiments, may include rubber bushings or the like that permit the floor  46  to translate and/or rotate as a cut crop is fed through the crop pickup portion  20  and thus exerts a force on the rotor floor  46 . The floor may also include one or more biasing members  49  that bias the floor  46  towards the rotor  28  and thus causes the floor  46  to substantially abut the rotor  28  when no force is applied thereto. 
     More particularly, as best seen in  FIG. 6 , when no force or relatively little force is applied to the floor  46 , the floor  46  is in a first position  52  where it generally abuts the rotor  28 . However, as the force acting on the rotor floor  46  increases, the acting force counteracts the biasing force thus moving the rotor floor downward and away from the rotor  28  to a second position  54 . It should be appreciated that the first and second positions  52 ,  54  are illustrative only and in practice there will be infinite positions for the rotor floor  46  to occupy rotates and/or translates during operation. 
     Aspects of the invention measure the force acting upon the rotor floor  46  and/or the displacement of the rotor floor  46  as an indication of how much hay or other crop is entering the agricultural baler  10  and thus the baling chamber  36 . More particularly, and with particularly reference to  FIG. 6 , as the agricultural baler  10  is towed in a forward direction (i.e., to the right as viewed in  FIG. 6 ), the crop pickup portion  20  engages hay or other crop  55  lying in a windrow, and conveys it towards the baling portion  22  via the rotor  28 , as discussed. In this regard, the hay or other crop  55  is forced between the rotor  28  and the rotor floor  46  at an impingement portion  56 . Due to the compression of the hay or other crop  55  between the rotor  28  and the rotor floor  46  at the impingement portion  56 , the hay or other crop  55  exerts a force on the rotor floor  46  causing it to displace. More particularly, the rotor floor  46  may angularly displace (as generally indicated by arrow  58 ), and/or may linearly displace (as generally indicated by arrow  60 ). 
     The force exerted on the rotor floor  46 , the angular displacement of the rotor floor  46 , and/or the linear displacement of the rotor floor  46  can be measured and employed in determining a rate of hay entering the agricultural baler  10  and thus the baling chamber  36 . In some embodiments, the speed of a portion of the crop pickup portion  20 , such as an angular velocity of the rotary rake  24  and/or the rotor  28 , is also used when determining the rate of hay entering the agricultural baler  10  and thus the baling chamber  36 . 
     The force exerted on the rotor floor  46  and/or the displacement of the rotor floor  46  can be determined using any suitable sensor  62  operatively connected to the rotor floor  46 . For example, in some embodiments the sensor  62  may be an angular displacement sensor that measures the angular displacement of the rotor floor  46  about a pivot axis, which, in some embodiments, may be located near a first end  48  of the rotor floor  46 . And in other embodiments, the sensor  62  may be a linear displacement sensor that measures the linear displacement of the rotor floor  46  at a given point of the rotor floor  46  such as, for example, a point near a second end  50  of the rotor floor  46 . In still other embodiments the sensor  62  may be a pressure sensor that measures a pressure exerted by the hay or other crop  55  on the rotor floor  46 . And in still other embodiments the sensor  62  may be a load cell that measures a load exerted by the hay or other crop  55  on the rotor floor  46 . 
     Any other desired sensor can be used to sense any desired metric proportional to a force exerted by the hay or other crop  55  on the rotor floor  46  without departing from the scope of this invention. Moreover, for embodiments where the metric can be measured without relative movement of the rotor floor  46  (such as, for example, when the sensor  62  is a pressure sensor, load cell, or similar sensor), the rotor floor  46  may be stationary (that is, not pivotably or translatably attached with respect to the rotational axis  49  of the rotor  48 ) without departing from the scope of the invention. Similarly, the rotational speed of the spinning part of the crop pickup portion  20  can be measured using any desirable sensor. For example, the rotational speed of the rotary rake  24  can be measured using a first speed sensor  64 , and/or the rotational speed of the rotor  28  can be measured using a second speed sensor  66 . 
     In some embodiments, the information indicative of the rate of hay or other crop  55  entering the baler  10  or other piece of equipment—more particularly, the information regarding the rotational speed of the rotary rake  24  or rotor  48  (referred to herein as “speed data”) together with the force, pressure, or displacement data associated with the rotor floor  46  (referred to herein as “force data”)—can be provided to a tow vehicle and/or an operator of a tow vehicle in real-time. This may aid the operator and/or the tow vehicle in making speed or other decisions when baling hay or otherwise picking up a crop. For example, the real-time data may be provided to the operator or another party for real-time monitoring of how much hay is being produced. In other embodiments, the agricultural baler  10  or other piece of agricultural equipment may most efficiently perform at a known throughput rate. Thus, by monitoring the speed of a portion of the crop pickup portion  20  with the first and/or second speed sensor  64 ,  66  and/or the force exerted on the rotor floor  46  by the sensor  62 , the throughput rate of the hay or other crop  55  being picked up from the field can be provided to the tow vehicle and/or to the operator of the tow vehicle (via a user interface on-board the tow vehicle) and necessary adjustments to speed of the vehicle and/or the PTO can be made until a more efficient take-up rate is achieved. 
     In some embodiments, adjustments to drive speed, PTO speed, or other parameter of the tow vehicle can be performed autonomously in response to the sensed take-up rate. For example, certain tow vehicles such as tractors may be outfitted with a universal Tractor Implement Management (TIM) system and/or an ISOBUS-compatible system. In such embodiments, an implement (such as the agricultural baler  10  or the like) can take control of the tow vehicle in some respects. More particularly, TIM systems similar employ the international ISOBUS standard that enables controllers of implements (such as, e.g., the agricultural baler  10 ) and the tow vehicle (such as, e.g., a tractor) to communicate and control one another. As should be appreciated by one skilled in the art, TIM systems reduce the amount of repetitive actions that must be traditionally performed by an operator of the tractor. As one example, when baling hay traditionally operators must stop the tractor each time the baling chamber is full to allow the baler to wrap and eject the fully formed hay bale. But in balers equipped with TIM, the baler may autonomously (i.e., without input from the operator) reduce the tractor&#39;s speed or stop the tractor when the bale is fully formed, and thereafter increase the tractor&#39;s speed once the hay bale has been ejected. 
     According to aspects of the invention, when agricultural equipment is equipped with a TIM system and/or an ISOBUS-compatible system, the TIM system and/or ISOBUS-compatible system may increase the tractor driving speed and/or the rotation speed of the PTO when the sensor data indicates that the hay take-up rate is less than ideal. Conversely, the TIM system and/or the ISOBUS-compatible system may decrease the tractor driving speed and/or the rotation speed of the PTO when the sensor data indicates that the hay take-up rate is higher than ideal. 
     Additionally or alternatively, the information indicative of the rate of hay or other crop  55  entering the baler or other piece of equipment can be stored via on on-board memory or the like for later transmission to a farm management information system (FMIS) or similar software package. In other embodiments, the data can be wirelessly transmitted to a remote personal computer, server, or other suitable device for later review and use by the grower using the FMIS or similar. As one example, the sensor data can be used to create a yield map or other graphical display, providing the grower with agronomic data for making future planting or treatment decisions for a given field. 
     The above described methods and systems may be more readily understood with reference to  FIGS. 7 and 8 , which schematically depict methods of collecting data using a material throughput sensing system including one or more sensors such as sensors  62 ,  64 , and  66 , and using data collected by the same to make a decision regarding towing vehicle speed, PTO speed, planting, treatment, and other decisions. 
     First,  FIG. 7  depicts a method  68  of adjusting an operating parameter of a piece of agricultural equipment according to some embodiments of the invention. At step  70  the agricultural equipment picks up a crop lying in a field. For example, when the agricultural equipment is a baler such as agricultural baler  10 , the crop pickup portion  20  engages the hay or other crop  55  lying in a windrow and flings it upwards and rearwards toward the baling portion  22 . At step  72 , the crop is conveyed to a feed mechanism of the agricultural equipment. Returning the example of the agricultural baler  10 , the feed mechanism may include portions of the baler  10  that convey the hay or other crop  55  through the baler  10 , and thus in some embodiments may be the rotary rake  24 , the rotor  28 , and/or the rotor floor  46 . In embodiments where the agricultural equipment is a combine harvester or the like, the feed mechanism may be a reel, auger, or other conveying portion of the crop gathering header. 
     At step  74 , a speed of at least a portion of the feed mechanism is measured. Returning to the agricultural baler  10  example, the rotational speed of the rotary rake  24  and/or the rotor  28  is measured using a rotary speed sensor  64  or  66 . And at step  76 , a characteristic proportional to a force being exerted on a floor of the feed mechanism is measured via a force, pressure, displacement, or similar sensor. For example, and returning to the agricultural baler  10 , a characteristic proportional to a force being exerted on the rotor floor  46  is measured using sensor  62 . Again, this sensor  62  may be any suitable sensor for measuring data proportional to a load sustained by the floor  46  including, but not limited to, a load cell directly measuring the force exerted on the floor  46 , a pressure sensor measuring the pressure exerted on the floor  46 , or—when the rotor floor  46  is movable—a displacement sensor such as a linear displacement sensor or an angular displacement sensor. 
     At step  78 , the sensor data is correlated to a throughput of material. More particularly, using one or both of the speed of the rotor or other portion of the feed mechanism (“speed data”) and a characteristic proportional to a force being exerted on a floor proximate the rotor or other portion of the feed mechanism (“force data”), a processor or the like determines the rate of material passing through the feed mechanism. This correlation may be done by, for example, inputting the speed data and/or force data into a predetermined equation or other algorithm, by referencing a lookup table that correlates the speed data and/or force data to rate of material passing through the feed mechanism, or by any other desired method. In the agricultural baler  10  example, the rotational speed of the rotary rake  24  and/or the rotor  28  as measured by the sensors  64  and  66 , respectively, together with the one of force, pressure, or displacement data as measured by sensor  62  is correlated to a rate of hay or other crop  55  entering the baling chamber  36  of the baler  10 . 
     At step  80 , material throughput data is provided to the agricultural equipment and/or an operator of the equipment. In this regard, the data may be outputted to a user interface of the equipment. Or the data may be provided to an electronic control unit (ECU) or other controller of the equipment in addition to or instead of outputting the data to a user interface. In the example of the agricultural baler  10 , the data may be provided to an ECU of a tractor or similar tow vehicle and used in connection with a TIM system and/or displayed on a user interface of the tractor. Similarly, in the example of a combine harvester, the data is provided to the ECU of the harvester and/or outputted to a user interface within the cab of the harvester. 
     Finally, at step  82  one or more operating parameters of the agricultural equipment are adjusted based on the material throughput data. For example, in the example of the agricultural baler  10 , if the data is outputted via a user interface or the like to the operator in real-time, and the operator determines that the rate of hay or other crop  55  take-up is less or more than ideal, the operator can increase or decrease, respectively, the driving speed of the tow vehicle and/or the rotational speed of the PTO. Moreover, if the agricultural equipment is equipped with a TIM system or other ISOBUS-compatible system or the like, the operating parameter may be adjusted automatically. For example, the agricultural baler  10  may determine that rate of hay or other crop  55  take-up is less or more than ideal, and in turn send an instruction to the ECU or other controller of the tractor or other tow vehicle to increase or decrease, respectively, the driving speed of the tow vehicle and/or the rotational speed of the PTO. Similarly, an on-board controller of a combine harvester or the like may automatically adjust one or more characteristics of the combine (driving speed, reel or auger speed, etc.) in response to the material throughput data. 
     In other embodiments, a farmer, producer, or the like may make one or more planting or treatment decisions based on a review of the material throughput data. This may be best understood with reference to  FIG. 8 , which is a flowchart schematically depicting a method  84  of making one or more planting or treatment decisions. At steps  86 ,  88 ,  90 ,  92 , and  94 , the agricultural equipment (e.g., a baler, combine harvester, etc.), picks up a crop in a field, conveys the crop to a feed mechanism, measures a speed of at least a portion of the feed mechanism such as a rotor of the feed mechanism, measures a characteristic proportional to a force being exerted on a floor proximate the rotor or other portion of the feed mechanism, and correlates the speed data and/or force data to a material throughput in a similar manner as discussed above with respect to steps  70 ,  72 ,  74 ,  76 , and  78  of method  68 , which will thus not be repeated in detail. 
     At step  96 , the material throughput data is transmitted to a processor remote from the agricultural equipment, such as one associated with a software program such as a FMIS program or similar software. This can be performed in real-time via, e.g., wireless communication between the agricultural equipment and a personal computer, server, etc., or the material throughput data may be stored via an on-board memory for later uploading to the FMIS program or similar software. At step  98 , the data is graphically outputted to a user (e.g., farmer, producer, operator, etc.). The data may be outputted in any desired format and in some instances is outputted in tabular format such as in a spreadsheet or the like, as a yield map, or in any other desired format. 
     At step  100 , one or more of a planting decision or a treatment decision is made based at least in part on the outputted data. For example, the farmer, producer, or operator, after reviewing the data, may determine a type of crop and/or amount of seed to plant in a field, an amount of fertilizer and/or type of fertilizer to apply to a field, an amount of soil conditioner or type of soil conditioner to apply to a field, among other determinations. In some embodiments, the farmer, producer, or operator may make targeted planting or treatment decisions based on the data. For example, in response to a yield map indicating that there was a lower material throughput (and thus yield) for a first part of a field than for a second part of a field, the farmer, producer, operator, or the like may target the first part of the field with a different planting, treatment, watering, etc., strategy in subsequent plantings. 
     From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious, and which are inherent to the structure. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense. Additional objects, advantages, and novel features of the invention will be apparent to those skilled in the art upon examination of the above or may be learned by practice of the invention.