To harvest the most high-quality hay or haylage, condition the crop and lay it in wide swaths. Both are essential for fast drydown and low field losses, say two University of Wisconsin researchers.
"When we started coming out with conditioners, people thought that, because we were conditioning, we didn't need to wide swath anymore," says Dan Undersander, Extension forage agronomist. "But it's really important to recognize that the two are totally different, and we need both. Conditioning helps the stems dry; a wide swath helps leaves dry."
Undersander and ag engineer Kevin Shinners say to start by mowing alfalfa at a 2-4" cutting height and grasses or alfalfa-grass mixes 3-4" high.
"Then we have to do a really good job of conditioning the crop," says Shinners.
Conditioning breaks stems and the waxy layer covering them, allowing water to evaporate. Shinners says Midwesterners should use intermeshing rubber rolls, while steel rolls are recommended in the West, where abrasive soils can rapidly wear rubber rolls.
"Our research shows that you don't see a lot of difference in the amount of conditioning that you get and the subsequent drying rate – as long as you do a good job of setting both rolls up," he says.
Conditioning is important, even when you're making haylage, Shinners adds. Fresh-cut forage is about 75% moisture and haylage is put up at 55-62% moisture.
"To move from 75% to 60% moisture you have to lose 900 gallons of water per acre," he points out. "You need to condition well in order to get that water to leave that plant."
Undersander thinks mowing without conditioning may be an option for growers who only make haylage, although they'll add up to four hours of drying time. But he recommends laying the crop in wide swaths – at least 60% of the cutting width – regardless of how it will be stored.
"What we've seen with wide swaths is faster drying all the time and higher forage quality about 70% of the time," he says. "We don't always get higher quality, but we always get faster drying."
He tells growers to choose mowing equipment carefully because some can lay swaths up to 80% of the cutting width while others only go to 40%.
Read more from Undersander and Shinners, plus stories on the tight hay supply-and-demand situation, round balers with built-in wrappers and more, in the August issue of Hay & Forage Grower.