More equipment manufacturers are introducing their latest offerings to the autonomous tractor system that Deere introduced (in Canada) in 2011, with Kinze and the Spirit the latest to join the trend.

Specifically, Kinze Manufacturing introduced its new system in an experimental exhibition at its headquarters in Iowa, in 2011 while the makers of the Spirit at Fargo, N.D. unveiled their entry last March.

In 2012, both companies took their systems to the field. Kinze hosted a recent media day in western Illinois, showcasing its Autonomous Harvest System with the help of three local farmers, each of whom tested the system for three weeks. Kinze provided the hardware for each farmer's combine, and equipped a John Deere 8530 with the autonomous equipment for each farm.

The returns on that system were all favourable, with one farmer saying he was pleased with the ease of use and the potential for freeing up someone to do "something else" on the farm. One demonstration at the media day showed a combine turning circles, with the grain cart capable of remaining precisely under the combine auger. That led one farmer to say that such precision was probably not possible with a human driver, without spilling some of the corn as it's harvested.

That seems to be a focus for Kinze: the human element. The skills needed to operate large-scale farm equipment with a level of efficiency are becoming rare. Combined with the increasing size of farming operations, the demand for this technology will continue to increase.

The other player entering the autonomous tractor parade is the Spirit. At a farm equipment show in North Dakota last September, Autonomous Tractor Corp.'s entry into the market was -- at first glance -- marked by the boxy appearance of its design. Not only is it rectangular, it's also missing a cab of any sort -- a move which the company's designer calls "the look of the future."

The goals, aside from providing autonomous controls for a grain cart, are efficiency and reliability at a lower cost: $500 per horsepower.

The design on the Spirit tractor actually takes a page from railroad locomotives, boasting a tubular steel frame and a diesel-electric power plant, which means there is no need for a transmission or differentials.

At 25,000 pounds, the weight of the tractor is another selling point, minimizing the potential for compaction, thanks also in part to its rubber tracks. Ballasting an additional 5000 lbs. is possible by adding water to its tubular frame.

If there's a drawback to Spirit's design, it's that it is a single-function unit, as opposed to the conventional cab-equipped tractor. A farmer can use it for little else but automated grain hauling. And yet Spirit's designer noted that little has changed in tractor design in the past 14 years; only the cab has been enhanced, with larger spacing, more luxury and environmental controls that are too expensive to incorporate into an autonomous design.

-- Ralph Pearce is a field editor for Country Guide at St. Marys, Ont.