Glen Cauffman believes Italian hay dryers can be used successfully on U.S. farms, but will require dramatic changes in haymaking practices.
“The dryers can do basically what the manufacturers are saying,” says Cauffman, Penn State University's manager of farm operations. “But it's an entirely different system.”
The past two growing seasons, Cauffman tested an eight-bale dryer imported by Feraboli. A similar Italian unit, Clim-Air, is being sold by Double D Tractor Parts, Sikeston, MO. Popular in Europe, both brands were introduced here last year, and U.S. growers are expected to start using them in 2005.
Cauffman used round bales, but the dryers will handle big square bales, too. Both models have two drying floors with tunnels and ducts inside them. An electric fan blows air over burners powered by diesel, propane or natural gas. At about 100°, the air moves through the tunnels in the top floor to three flexible tubes at the opposite end. Those tubes carry the air to the other two floor tunnels. Bales are dried from the top and bottom at the same time.
Depending on the model, from eight to 24 bales can be dried at a time. The manufacturers claim hay can be dried from 35-40% moisture to 12% for about $10/ton.
Cauffman says artificial drying should permit growers to reduce alfalfa leaf loss, improving hay quality. His data hasn't been analyzed yet, so he can't say whether they're likely to harvest enough higher-quality hay to recoup the initial investment plus operating costs. But he offers the following advice on how to get the most benefit from a dryer.
First, with limited dryer capacity, you can't wait for a three- or four-day weather window and then mow a lot of hay. You'll have to cut a few acres often, regardless of the forecast.
“I won't say every day, because some days it's going to be pouring,” he says. “But if it's a one-day period without rain, you'll mow some hay.”
That makes dryers best-suited to small and medium-sized haying operations. “Large farmers can't mess with mowing 10 acres at a time,” points out Cauffman.
He suggests field-drying the hay to storable moisture if weather permits. In this hay dryer system, though, it'll usually be baled early, sometimes at very high moisture levels.
“That will be a challenge,” he says. “We found that, the wetter the hay is when it's put into the dryer, the less uniformly it will dry. We had a whole lot more uniformity with 30%-moisture bales than with 50% moisture. And when we dried some as high as 70%, it was worse yet.”
Air follows the path of least resistance, so the densest bales or parts of bales are the slowest to dry. Minimize that problem by striving to make uniform bales.
“The uniformity of baling is the most important part of the management of the hay dryer,” says Cauffman. “And that involves very uniform windrows, driving at a consistent baling speed, and making the bales a consistent size and density.”
He tried several methods of enhancing bale uniformity. One that worked fairly well was setting the mower-conditioner to leave a swath the same width as the baler pickup, and not raking the hay. Mowing a wide swath, tedding with a rotary tedder and then raking the hay into windrows exactly as wide as the baler pickup worked even better.
Determining when bales are dry is another issue. According to Cauffman, electronic moisture probes aren't accurate enough. So he installed load cells in the dryer and recorded the total weight of bales going in. Then he pulled core samples, accurately moisture-tested them with a microwave or Koster tester, and calculated the weight at which the bales should be removed.
He'll suggest to the manufacturer that load cells be added. He also recommends that each dryer come with a shroud that can be dropped down to keep cold air away from the bales. Sometimes, when warm, moist air leaving the bales meets colder ambient air, moisture condenses on bale edges. A shroud would reduce the temperature difference at the bale surface and eliminate condensation.
It would pay dividends during late cuttings, which are difficult to field-dry.
“At least here in Pennsylvania, we get some nice hay in the fall,” says Cauffman. “It's one of the top-quality cuttings of the year.”