WEST LAFAYETTE, Ind. — Forage producers need to get out into
their fields to assess the health of plants as they begin to break dormancy
after a particularly harsh winter, a Purdue Extension forage specialist
Forage growing in areas affected by below-zero temperatures
during periods of no snow cover are the most at risk for damage because snow
serves as insulation for the plants and protects them from bitter cold.
Low-lying parts of fields where snow accumulated and then
iced over also are at risk for loss from suffocation.
“The lesson here is to get out there and observe those
fields,” Keith Johnson said. “Now is the time. As the crop breaks dormancy,
producers need to check to see if plant green-up is occurring. If that’s not
happening after several days with temperatures in the 50s and 60s, it’s time for
Green-up usually happens around the third week of March in
southern Indiana, then 10 or more days later in the northernmost part of the
Although soils have stayed frozen for most of the winter,
Johnson said alfalfa growers still should pay attention to root heaving. When
some soils, especially those that are saturated and with some clay, go through
multiple freeze-and-thaw cycles, it can push the alfalfa plant up out of the
Other areas of plants that should be inspected include the
crown and taproot.
“Growers should take a tool along with them as they scout so
they can slice into the crown of a few plants to see if the bud tissue is
cream-colored and green,” Johnson said. “They also can inspect the root for
cream-colored tissue. If they find dark brown tissue, that’s not a good
Farmers who find problems in their fields have a few options
to remedy them.
If the problem is severe enough, Johnson said it might mean
using land previously intended for another crop to instead start a new forage
stand. But if the problem area is limited to one large section of a field, it
might be possible to start over just in that area.
“Farmers do have the option to patchwork in new seed in
areas of loss, but they need to be aware that it will be a little bit tricky to
manage for the first season because forages will need to be harvested at
different times,” Johnson said.
For fields where the stand might be thin, producers can
consider over-seeding. Using a broadcast seeder on an all-terrain vehicle is
typically a preferred method to avoid taking tractors and drills into soggy
But before growers over-seed, Johnson said they need to look
carefully at soil fertility and residual overgrowth and develop a plan to fix
“Growers need to look for underlying issues that would cause
seedling failure,” he said. “Some of those issues include low soil pH and poor
fertility. They need to make sure that residual growth from 2013 is no more than
4 inches tall so that the seed can reach the soil surface.
“Also, overseeding alfalfa seed into a field that currently
has alfalfa is risky because the currently established alfalfa produces a
chemical that hampers the establishment of new alfalfa seedlings.”
The timing of over-seeding also is crucial. Johnson said
broadcast seeding should be done at green-up because seedlings will have to
compete with perennial plants breaking winter dormancy.
Finally, growers need to make careful seed selections,
partially based on field history. For example, the weed history of a field would
have an effect on seed selection because herbicides used to control broadleaf
weeds also kill perennial broadleaf forages.
It’s also important to choose a seed that mixes well with
the forages already growing.