Grower Profile: The Mitchell Farm, Part II

Grower Profile: The Mitchell Farm, Part II

Clay Mitchell can’t sleep at night when something in his farm has been left to chance. That’s the impression we were left with last fall when we spent some quality “cab time” with this eastern Iowa grower.


Technology is truly a tool of accuracy for The Mitchell Farm, where automatic steering was adopted in 1999 — well before it became agriculture’s coolest tool.

Mitchell also realized the power of the Internet and computer networking very early on. He harnessed the farm’s HAM radio tower, using it to mount multi-channel radios that transmit both real time kinematic (RTK) signals and a local area network (LAN). The base radio and strategically-placed repeaters allow Mitchell to employ the Trimble Autopilot and John Deere Autotrak automatic steering systems he uses at any of the fields he owns or rents.

The LAN ties him into his farm system as well as the Internet, allowing him to control virtually any aspect of his farm from anywhere he carries his laptop within range of the network.

Cool? Yes, but Mitchell has a reason for everything the farm adopts in terms of technology. The automatic steering program was brought on to bring dead-on accuracy to planting and strip tilling, and Mitchell finds “almost right” unacceptable.

“Because we are totally dependent on automatic steering technology for every operation, something that works 99% of the time isn’t good enough,” says Mitchell. He uses the Trimble Autopilot on his Case IH equipment, including an AFX8010 combine and a MX270 tractor, as well as his Deere 4700 sprayer. He uses Deere’s Autotrak on his 8520 tractor.

RTK-based automatic steering has provided other benefits as well, including improved tracking to reduce compaction and faster, more efficient movement through the field.

All this has reaped clear benefits at the end of the season — in 2003, corn yield averaged 215 bushels per acre, about 58 bushels better than either the state or the county average. It’s the farm’s biggest trouncing of the averages to date.

More In 2004

Constantly agitated by the less-than-perfect, this past year Mitchell implemented some technology to improve the efficiency and accuracy of his John Deere 4700 sprayer.

The main efficiency drag on spraying has always been outlining the waterways, while spray accuracy is always a concern, even when using GPS guidance systems. Mitchell wanted more.

His ultimate goal was to gain control over sections of the boom automatically, so that when the sprayer boom was passing over a non-target area, be it a waterway or a section already sprayed, it would automatically shut off that section.

To accomplish this, Mitchell combined KEE Technologies’ ZYNX X15 controller with Trimble’s Autopilot steering. The ZYNX provides the capability of controlling individual boom sections, and the Trimble RTK system delivers the accuracy.

On the boom, Capstan solenoid valves were placed on each nozzle, and the boom section valves were removed to keep the boom at a constant pressure. By doing this, spray on/off control is almost instantaneous at the boom section, a critical feature when working near waterways.

Bottom line? Efficiency gains in 2004. Mitchell says he’s realized a 30% efficiency gain for spraying, and a 20% savings on crop protection inputs due to increased accuracy.

In the future, Mitchell says he’s working on the next generation of spraying accuracy, which will allow him to turn individual nozzles, rather than just boom sections, on and off as product is applied.

Editor’s note: This article first appeared in the Winter 2004 issue of PrecisionAg Special Reports.