A trip to the Guidance Counselor may bring back images of High School, but with the current interest and adoption of GPS technology in agriculture, I find myself being put in the role of GPS Guidance Counselor.

GPS technology has been used in agriculture for over 10 years. From locating soil fertility sample points and variable rate fertilizer applications to making yield maps with data collected by GPS equipped combines. But over the last year we have seen a tremendous increase in the adoption of on-farm GPS guidance. Previously you were most likely to find these systems on commercial application equipment. But with improvements in ease-of-use and lower cost many farmers have purchased or are investigating the equipment. Some systems provide a indicator helps the driver steer the equipment accurately while others actually take over the steering task altogether.

Why are so many farmers excited about this technology? One big reason is improved field efficiency and reduced overlap. This can provide big cost savings in reduced fuel and pesticide cost. Reduced overlap and higher speeds also means you can cover more acres per hour. Reducing labor cost or allowing you to farm more acres with the same equipment and labor. This technology also allows you to continue field operations in difficult situations such as night, dust and fog. There is also a comfort factor that may reduce fatigue allow for better multi-tasking by the operator. The operator may be do a better job of monitoring the machinery and correct problems quickly that may have escaped notice while busy with driving tasks. Timely field operations can also have yield benefits when work is done at the optimum timing.

Improvements in GPS technology have provided a complete range of options that allow farmers to select an accuracy level that fits their goals and budget. Normal GPS without a source of signal correction has limited accuracy. Thirty feet will help you easily find an airport or campground and even put you close enough to a "geo-cache" that you can find the treasure with a little visual searching. However, thirty feet will leave a pretty big gap in a field.

A variety of correction sources are available and as you would guess higher accuracy comes with a higher price tag. Free correction from the WAAS system can improve accuracy to levels that are suitable for some guidance applications. Coast Guard navigation beacons located along the major rivers and the Great Lakes also provide a free source of GPS signal correction that will work with some GPS receivers. Several companies offer subscription based satellite and ground based GPS correction services. The top end correction is generally considered to be RTK correction which relies on a local ground based receiver/transmitters to provide a correction signal. Many areas of Illinois are already covered by RTK transmitters.

Before you make your trip to a Guidance Counselor think about what your goals are and what is your budget. The Ag Economics Department at Kansas State created a spreadsheet that will help evaluate the return on investment of a guidance system that can be downloaded for free from http://www.agmanager.info/farmmgt/machinery/.