Snow may be covering the ground most places in Iowa, but the planning and planting of the upcoming grazing season continues this month at the CRP Research and Demonstration Farm north of Corning in southwest Iowa. Farm manager Dave Fuller has already completed the frost seeding of legumes into the pastures that will be enhanced with the legumes growing there in 2008.
He did this by broadcasting the red clover, trefoil and alsike clover seeds over the ground and snow. Those seeds will eventually land on the ground beneath the snow and then work into the frost cracks of the soil, planting themselves.
"We use both frost seeding and mechanical interseeding with a drill to add legume seeds to our rotational pasture paddocks at this farm," he explains. "We seed legumes into one-third of our acres each year, so we have the entire farm reseeded to legumes every three years."
Broadcast has some benefits over drilling
Broadcast frost seeding works best on thinner stands of grass, or where the grass has been grazed heavily in the fall. "We will pull a drill behind a tractor this spring to guarantee the best soil planting conditions on our thicker established grass stands," says John Klein, the CRP farm's project manager. "We want the interseeding to be completed by the first of April if possible.
"Because the broadcast frost seeding is not as efficient as mechanical planting, we do use 50% more seed per acre," he says. "In our case, we will frost seed 5 pounds of red clover, 4 pounds of birdsfoot trefoil, and one pound of alsike clover while the ground is still frozen solid. After the thaw, drilling conditions must be dry and it is more difficult to find a good day to drill the seed into the ground."
For drilling, he uses 3.5 pounds of red clover, 3 pounds of trefoil and three-fourths of a pound of alsike clover. Drilling is usually better for planting establishment, and it requires less seed. Unfortunately, it also requires much more work, equipment and time at a time when many other things also have to be done if you are a farmer. "That is why we encourage frost seeding now as a workable option for improving pastures." says Klein.
You can rent a seeder from NRCS office
Old seeder carts are difficult to find for broadcast seeding, but often newer equipment can be located. If you are interested in renting a seeder, contact your local NRCS office.
In the case of the CRP Demonstration Farm, the local Adams County Soil and Water Conservation District has a Vicon broadcast seeder that fits on the three-point hitch of a tractor. This seeder can be rented at a low cost to grassland farmers. It has a large hopper, and a swinging arm that can be adjusted to both width and speed to broadcast the seed. For smaller jobs, they also have a rear-mounted broadcast seeder that fits on a four-wheeled ATV.
One good thing about broadcasting over snow is that you can see exactly where the seeds land on top, notes Klein. Then you can adjust your width and tractor speed accordingly to get just the coverage you want.
The CRP Research and Demonstration Farm is a project of the Southern Iowa Forage and Livestock Committee. They are grazing education organization striving to retain grassland and grazing as both a viable and economic advantageous commodity for the marginal lands in southern Iowa.
The SIFLC is based out of the ISU Extension office in Corning. Dave Fuller of Corning is the drill manger and also does frost seeding at the farm. SIFLC has a Great Plains grass interseeder drill that also can be rented for use by private landowners in counties surrounding Adams County. Use of that drill is on a "first-come, first-served" basis, and a list is already growing for Spring use, he says.