After watching Claas, John Deere, Krone and New Holland self-propelled forage harvesters compete against each other in Chopper Challenges the past three summers, Dan Lamb can’t say one brand is better than the others.

“If you’ve got a good dealer in your area and he’s very attentive and wants to make sure you succeed, then that’s the brand you should buy,” suggests the Bakersfield, CA, custom chopper.

He organized the one-day events, all held near Bakersfield, in which the four brands squared off for top honors in tons of corn silage chopped per hour, per horsepower and per gallon of fuel. Silage processing quality was also evaluated.

There were differences among the machines in each of those measurements, but most were insignificant, says Lamb. Claas choppers showed a consistent edge over the other brands, but they were fully broken-in machines supplied by custom harvesters, while some of the other choppers were new. Due to that difference, plus variations in cut length and other factors, none of the comparisons were as fair as Lamb would have liked.

Perhaps the most important finding was the impact of cut length on chopping efficiency across forage harvester brands. Fuel consumption per ton increased by 53% and chopping capacity dropped by 42% as particle length went from 17 to 11 mm, according to calculations by Brian Marsh, University of California farm advisor in Kern County.

Those figures underscore the importance of setting the machine to achieve the targeted chop length and harvesting the corn crop within the correct moisture range, says Marsh. He collected and evaluated forage samples at the challenges and analyzed the data.

“If it’s beyond maturity and has started to dry down too much, then it needs a shorter chop length in order for it to pack better, and that’s a huge cost,” he says.

Marsh’s data also show that significant amounts of time were lost turning on field ends.

“We have concluded that bigger heads can lessen the turn time,” Lamb reports. “We’re putting 10-row heads on our 600-hp machines.”

The Chopper Challenge idea was first discussed by Lamb and Jon Orr, an Apple Creek, OH, custom chopper, in 2007. They figured head-to-head competitions would show manufacturers the strong and weak points of their machines, ultimately resulting in better forage harvesters.

“The idea was we as customers need to drive this market instead of the manufacturers driving it to us,” says Orr. “(We thought) it would be great to compare these machines side by side, so we can help improve them.”

Lamb lined up the choppers and the drivers, all experienced with the models they would be operating. He also provided the fuel and trucks for each challenge, while U.S. Custom Harvesters, Inc., paid for the silage-processing evaluations.

Marsh designed the competitions as he would research trials, with three replications. Chopping times were carefully recorded for each four-acre plot, and fuel consumption was measured. Trucks were weighed loaded and unloaded, and silage samples were collected for moisture testing.

Two truckloads per plot were sampled for cut-length evaluations using a Penn State forage particle separator. Following the recommended shaking procedure, Marsh weighed the forage in each box and used a calipers to measure 20 randomly selected stalk pieces from the middle one.

While the goal was to run fair competitions for all the forage harvesters, making everything equal proved to be a daunting task. Lamb wanted to use new choppers, but ended up with a mix of new and broken-in machines. All were carefully adjusted for a specific cut length and were operated prior to the first two challenges to make sure they were visually cutting similar lengths. But actual cut lengths varied during all three contests.

In addition, one chopper in the first challenge had an engine fuel-line problem, one machine in 2011 and another in 2012 had the wrong engine software, and a corn head wasn’t properly adjusted at the start of last year’s competition.

Four choppers with similar horsepower ratings competed in each of the first two challenges, but the 2012 event had five models: Claas Jaguar 980, John Deere 7950 Prodrive, Krone Big X 1100, New Holland FR 9090 and New Holland FR 9060. The Big X 1100 had 1,031 engine horsepower, the FR 9060 had 544, and the other three models ranged from 800 to 860 hp. All had 25’ heads chopping eight 38” rows per pass, except the FR 9060, which had a 20’, six-row head.

All the machines were set for 16-mm theoretical length of cuts, but actual cut lengths varied from 15.1 to 17.8 mm. Crop-processor roll gaps were all set at 2 mm.

Marsh’s data show that the higher-horsepower Krone machine chopped the most tons per hour, as expected, and the most per gallon of fuel. It also had the shortest chop length and highest processing score. The Claas chopper placed second in tons chopped per hour and per gallon, but had the longest chop length. The John Deere and New Holland FR 9090 choppers performed about equally in tons per hour and per gallon. The FR 9090’s chop length was at the 16-mm target, while the Deere machine’s was 15.2 mm.

The smaller FR 9060 chopped fewer tons per hour than the others and had the lowest processing score, but was competitive in tons chopped per gallon of fuel.

To chop efficiently, an operator has to know how to adjust his harvester, says Orr. “The machine is only as good as the guy who sets it up.

“We try to make the Chopper Challenge as equal as possible, but there are so many factors playing into it that it would take at least three days with a crew tuning and dialing and tweaking to make it perfect,” Orr adds. “We tried as hard as we could, but it seems like we weren’t where we needed to be.”

Still, he feels the challenges were worthwhile. Company representatives were at all three events, and two brands now have better crop-processor drive mechanisms, he says. “We helped drive the improvement of the machines, and that was the goal.”

Orr hopes another Chopper Challenge will be held this year; most likely it would take place in conjunction with another event involving forage harvesters.

Lamb plans to quantify the impact of cut length on fuel consumption, output and processing score. Using his chopper, he’ll chop at 2-mm intervals ranging from 10 to 20 mm. Then he’ll know the setting at which his machine operates most efficiently, how much higher his costs will be if a dairy wants a short cut, and the effect on processing if a long one is requested.

Chopper Challenge results are posted on the Kern County Cooperative Extension website at http://bit.ly/16sg80k.

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