Self-propelled forage harvesters are working about 80% of the time they're in the field, estimates Nate Dudenhoefer, University of Wisconsin ag engineering graduate student.

He conducted a study during the 2009 corn silage harvest, looking at how forage harvesting systems could work better together to maximize their use.

“Accounting for the time turning on headlands, and that most people do stop to change trucks and for inoculant, I would be very surprised if the average is above that,” he says.

“If you could eliminate turning on the headlands by changing field patterns and had enough shifts that you weren't stopping for meals, I think you could get over 90% (field efficiency). But in corn you generally can't eliminate headland turns.”

More data, from seven farmers in 85 fields, will be analyzed later.