The reason many planters are ordered today without markers is that more people are using RTK GPS, which gives accuracy down to the inch, more or less. It requires either an in-field station or a tower in the area – not a necessity for some folks, but when woods interfere with GPS signals or you just have a weak signal, using "normal" auto-guidance technology can become a headache.
That's why there are several reasons RTK GPS is growing in popularity. It's repeatable, which means you can come back on a sidedress pass in corn and hit the sample pass dead on. It's even accurate enough to use auto-guidance and hands-free driving while sidedressing corn, some say.
For someone who grew up sitting on the back of a four-row three-point hitch cultivator because his dad wasn't accurate enough to always stay off the rows driving with his hands, it's mind-boggling.
Officials demonstrated the tech while planting a recent soybean trial at the Meigs Horticulture Farm. It's part of the Purdue University farm system, and loosely linked to the Throckmorton Research Center. Both are located near Romney.
The driver put the border pass on the south end of the plot, after running a border pass on the north end of the plot, setting his A-B line on that north-end border pass. Through magic which is really computer calculation based on satellite signal and RTK differential correction, every pass from then on, based on the six-row planter entered into the computer as the implement being pulled, lined up perfectly. It was hands-free driving.
The real eye-opener was when the last pass was perfect. There was just enough room on either side of what was planted to fill in the gap when he reached the south end of the plot. To one who has typically seen the gap be too wide or too narrow when guessing, it was again, mind-boggling!