Mechanization and materials handling basics

  John W. Bartok, Jr.

Many growers who have adopted energy conservation and heating fuel alternatives during the last several years have realized significant savings. But still the largest cost in plant production is labor. Equal or greater savings can be obtained by incorporating material-handling techniques and mechanization into a growing operation.
 
A good starting point for evaluating labor efficiency is to collect data on which operations require the greatest amount of time. Container filling, transplanting, hand watering, container spacing and plant selection for shipping require some of the greatest use of labor. These tasks are the ones that should be evaluated first for improvements.
 
Equipment is available for almost all greenhouse tasks, but not all of these tasks should be mechanized, especially for growers with only a small amount of production area. Some of this equipment is very expensive. Other machines are operated only a few days during the year. Purchasing decisions need to be made only after considering several factors.

Keep things simple
An understanding of how a piece of equipment works is important. Low-tech equipment generally requires fewer adjustments, less maintenance and uses standard parts. It is easier to upgrade a basic system than to replace a complex one that doesn’t do the job. I frequently see expensive equipment sitting idle in a corner of the greenhouse because it didn’t perform the way the grower had hoped.

Be conservative
Have a plan for what you want to accomplish, but limit the amount of change you institute at one time. Be conservative in your expectations of what equipment will do. It may take a while to make the proper adjustments.

Thoroughly analyze your needs
Equipment is expensive to own. Consideration should be given to where your resources will provide the greatest return. For example, an automatic watering system that can be used year-round may be a better choice than a precision seeder that will be used only 10 days a year.
 Compare alternatives on a simple payback basis. Simple payback in years is calculated by dividing the initial cost of the new equipment by the savings realized per year. A good payback is two to four years.

Design an efficient facility
Design your facility for efficient materials and plant movement. Reduce unnecessary transport, combine different tasks into one transport if possible and transport by the shortest route. In developing a layout, decide whether receiving and shipping should be separate or in the same location. Provide concrete walkways to handle the volume of materials moved.

Provide adequate storage space
Provide space for storage of growing media, containers, supplies, tools and spare parts. Locate the things that are used frequently near the point of use. Label everything to reduce time spent looking for materials.

Mechanize jobs
Mechanize or automate jobs that are repetitive, tedious or time consuming. These are usually the easiest tasks to mechanize and result in a significant labor savings. Considerable equipment has been developed for most of these jobs. Container filling, plant spacing, moving plants and watering are good examples.

Reduce labor requirements
Install equipment that reduces peak period labor requirements. Plants can be moved more quickly by carts or conveyors than by hand carrying. This type of equipment may also reduce the need to hire and manage more employees.

Pace employees
Select equipment that will pace workers. Conveyor belts work well for potting, transplanting and packaging, providing uniformity and consistency. A variable-speed motor adjusts the belt speed for different operations.

Reduce the amount of walking
Walking adds considerable time to the cost of plants. An average time to pick up or set down a flat of plants is 1½ seconds. Carrying or walking can be figured at 4 feet per second. At a $10 per hour labor rate, making a round trip 10 feet away to place a flat of plants on a bench adds 2 cents to its cost. Walking to the far end of a 100-foot greenhouse costs 15 cents. Consider how many times a flat or pot is handled before it is sold.

Standardize your operations
Keep the number and types of containers used to a minimum to reduce inventory and the time needed to make changes to equipment. Where possible, ship in standard units such as carts or pallets. This simplifies loading and invoicing.

Consider alternatives
Renting, leasing or sharing with a neighbor allows the use of equipment for short periods of time without a large investment.

Purchase machinery that can be expanded.
The reserve capacity will be useful for growth in a business or changes in the production system.

Select standard equipment
Select equipment that is manufactured with standard parts. Delays in receiving special parts to repair a down machine can interrupt a production schedule. Standard parts such as belts, drive chains, pulleys and sprockets can frequently be purchased locally. Critical spare parts should be kept on hand.

Train employees
Train employees for the tasks they are to perform. Utilize experienced workers or videos to show the most efficient methods of operation.

Ensure employee comfort
Employee comfort and safety is important. Provide adequate light levels (50–75 footcandles), heat (60ºF-68ºF) and cooling in work areas. An employee rest area with lockers, tables, vending machines, refrigerator and microwave improves lunch and break times and employee morale 
 

John Bartok Jr. is faculty emeritus, University of Connecticut, Department of Natural Resources Management and Engineering, jbartok@rcn.com.