Wisconsin winterkill alfalfa losses could exceed 1 million acres, says Dan Undersander, a University of Wisconsin Extension forage specialist. That huge number could represent roughly 50% of the state’s alfalfa crop.
Exact losses are "difficult to quantify because often losses are portions of fields…. Losses are generally any lower spots in the field," he says.
For fast regrowth, agronomists generally recommend planting seed oats and peas for haylage harvest. "But we are generally out of peas and oats is running short," says Undersander.
"We do not recommend seeding alfalfa back into the same field [due to autotoxicity concerns] unless the initial seeding was last year. Little to no alfalfa seed left for reseeding at this point."
Another alternative is BMR sorghum-sudangrass for silage, baleage or hay. Corn silage is another option if producers don’t need feed immediately and an wait for fall harvest. Nitrogen credits for a corn crop should be based on the alfalfa stand present last fall, says Undersander.
More alfalfa winterkill resources are available here.