Auto-steer technology has revolutionized the way America’s farmers drive planting and harvesting equipment across their corn, soybean and wheat fields.
Evaluate guidance systems to select the one that best fits your farm
Setting goals and taking small steps are almost always good strategies when considering new technology for your farm. For instance, a precision guidance system with centimeter-level accuracy will likely be the standard in the future, yet few applications today require it. In most cases, you can get the results you need from a lower-accuracy GPS guidance system.
Randy Price, Kansas State University Extension ag engineer, advises farmers to evaluate how they plan to use a precision guidance system instead of getting hung up on accuracy levels.
"The caliber of the system you need depends on the level of accuracy your specific applications require," he says.
Correction services are designed to help farmers monitor and minimize equipment drift that occurs during tillage, planting and harvesting.
"The biggest value is the increase in field efficiency, which results in the reduction of labor and other costs," Price says.
By reducing overlap and input usage, farmers save 10% to 12% on average each year on input costs, says Amy Winstead, precision ag manager for Alabama Farmers Cooperative Inc.
Farmers also benefit from many noneconomic factors that correction services provide, such as reduced operator strain and fatigue, Price adds.
The precision guidance systems on the market today fall into three accuracy categories: submeter, decimeter and centimeter. Submeter systems include WAAS (Wide Area Augmentation System) and John Deere’s StarFire 1. StarFire 2 and Trimble’s OmniSTAR provide decimeter accuracy, and RTK (real-time kinematic) provides centimeter accuracy.
Submeter accuracy. WAAS is a free, government-managed correction service, such as
StarFire 1, that provides farmers with 6" to 12" pass-to-pass accuracy. OmniSTAR requires an annual subscription fee and offers 6" to 8" accuracy. RTK systems are the most costly, but they provide up to 6" pass-to-pass accuracy.
Pass-to-pass accuracy, also known as relative accuracy, refers to how far off course you are from one pass to the next in the field. Accuracy is typically measured in 10- to 15-minute intervals, roughly the time it takes for a farmer to make a pass in a field.
Field operations performed at faster groundspeeds or shorter time between passes can use less efficient guidance systems, such as WAAS, without apparent errors, Winstead notes. "This result
occurs because drift accumulation over a short period is small," she says.
- January 2012