A number of low-lignin alfalfa varieties are slated to hit the market in 2016, says Dan Undersander, a University of Wisconsin agronomist.
While seed supplies might be limited—and at least one of the genetically modified (GM) versions will be limited to east of the Rockies—farmers should start thinking about how to manage this higher digestible forage.
Expect lignin levels to decrease 5% to 15%, with the GM versions to decrease the most, he says. “The value of decreased lignin will be increased forage quality and wider harvest windows,” he says.
The lower-lignin alfalfa will allow for higher quality if farmers opt for their standard 28- to 30-day harvest interval or for greater total tonnage by going to a 35-day harvest interval and one less cutting.
For now, Undersander is recommending farmers make their first cut at the same time as conventional varieties. The first crop, usually grown under cooler and less intense sunlight, tends to lodge if it is left in the field too long.
After the first cutting, Undersander says farmers can then go to the longer harvest window to get greater yield. Earlier studies show overall yield will increase by about 1 ton per acre while achieving the same quality as conventional alfalfa cut five days earlier.
The yield advantage is about 17% in the second year of the stand and 25% in the third year. Plus, harvest and labor costs will decline with one fewer cutting. Winter survival also might be greater since the plant is less stressed under a three-cut system.
Farmers may need to use fungicide more frequently with longer harvest windows, however. Leaf diseases have longer to establish themselves and cause damage, so leaf loss could become a concern.
Additionally, once cut, the crop might have to be handled more gently to avoid leave loss. Mergers tend to be better than rakes because of the way they combine windrows. Tedders should be avoided because they can be pretty rough on plants. “Every pass with a tedder could reduce leaves by 5%,” Undersander says.
All the low-lignin varieties being offered for sale in 2016 will also be Roundup Ready, which means there will be technology fees along with higher prices for the seed itself. “Low-lignin alfalfa seed will not be cheap, but it will be worth it,” Undersander says.