This article was originally published in the September 2014 issue of Farm Equipment's Sourcebook.

Of all the major field operations, most industry observers see advancements other than speed alone, playing a more significant role in improving crop harvest productivity. And while the narrow planting window seems to get the most attention, a narrow harvest window often causes the farmer as much heartburn.

According to Jasa, combines continue to get bigger and bigger to increase harvest capacity. “They’re talking a little bit about speed, but they keep making them wider and wider.”

“Today, we’re talking Class 9 combines and 40-45 foot headers,” Fulton says. “A few years ago, a 35 foot header might have the been the largest available.”

Jasa adds, “You get a machine that big with that kind of capacity, anytime it’s sitting still, you’re losing money. The problem in harvest isn’t with the combine. It’s with the rest of the grain handling system. Do you have the trucks to keep up with the combine? Do you have the augers to put it in bins once you get to the farmstead or are you waiting in line at an elevator? If I’m sitting in line with 10 other semis at the elevator, a bigger, faster combine doesn’t make sense.”

Purdue’s Buckmaster says that boosting the per-hour speed of corn harvesting is dependent on many variables, including terrain, the throughput capacity of the harvester’s head, horsepower and traction. Faster combines require more horsepower, which makes more sense in a smooth field in, say, Iowa or Nebraska, which produces higher than normal yields. But in eastern farm fields, areas like Pennsylvania and New York, for example, the extra horsepower would be wasted because rolling terrain and smaller fields naturally lead to more time spent in transition.

“Plus a header won’t work well above a certain threshold, say, 8 mph,” he adds. “You can’t go faster than what the head can handle. For example, you could put a huge engine on a combine with a 6 or 8 row corn head and theoretically go 12 mph. But practically and functionally, you can’t do that because the head won’t effectively gather corn at that speed, so you’d have wasted horsepower. In that case, the only way to increase capacity is to go wider.

“For maximum productivity, these machines require a good balance of width, threshing capacity and power that considers the terrain and expected yields,” Buckmaster says.

Nonetheless, the Peters brothers say that combines have gotten faster over the years. “Back in the day when you were running from 3-3.5 mph we thought that was pretty much it. Today, it’s nothing to go 6 mph with a 12 row corn header through 200 plus bushel corn. This is commonplace with 40 foot draper running 7 mph,” says Jon Peters.

Terry Peters believes the bigger breakthrough came with the development of the draper head. “It was a huge improvement because it feeds so evenly vs. an auger. It hugs the ground better, and the cutter bar flexes so much more than an auger machine. Basically, it made 4 combines act like 5. They didn’t change the combines at all, just the way it feeds the crop so evenly. You can combine an hour longer when the dew comes out at night.”