MORE THAN 1,000 no-tillers from seven countries gathered in the Crossroads of America this January to learn from some of the most experienced no-tillers and respected experts at the 2016 National No-Tillage Conference.

For some farmers, no-till is all they know. That's the case for Joe Zenz, who took up the practice when he started farming 20 years ago. A neighbor of veteran no-tiller Maury McLean, Zenz joined an informal partnership with him and his son Paul in 1996, and learned how to no-till under McLean's guidance.

The motor begins to hum and the propellers begin their increasingly rapid revolutions. A gentle upward tilt of the joystick by the owner and the rotocopter is airborne — slowly elevating as it drifts over a cornfield to capture hundreds of images that will be processed and analyzed.