If baled at less than 30% moisture and properly protected, corn stover destined for cellulosic ethanol production will hold its quality during long-term storage, says Matt Darr, Iowa State University ag engineer.

His research has shown that stover bales stacked on field edges in fall, and later in biofuel-plant stackyards, sweat out significant amounts of moisture, eventually reaching an equilibrium moisture content of 16-18%.

“We’re not as concerned as we were three or four years ago on storage because we’ve seen this equilibrium process a number of years in a row and feel confident about the storability of stover if it’s harvested at less than 30% moisture content,” says Darr.

However, square bales must be covered to keep rain out, he adds.Steel buildings or hoop barns offer the best protection, but tarps are almost as effective at much less cost. In round bales, corn stover doesn’t shed water as well as most other forages, so covering those bales may be beneficial, too.