by Scott Wohltman
The alternating mild conditions mixed with frigid cold temperatures we are experiencing are not doing pastures or hay fields any favors. Depending on region, livestock type, and forage source, it is safe to say many producers could be planning to augment forage stands as soon as possible.
Frost-seeding clovers into poorly producing or grass-dominated pastures by broadcasting in late winter is a practice that has been done for years. Adding legumes into pasture improves grazing quality and increases the forage amount that can be removed (up to a 50 to 100 percent increase in production when using legumes as a small percentage of the grass pasture).
Introducing a legume into a grass pasture can also reduce the amount of applied nitrogen fertilizer since the legume will fix nitrogen and provide the existing grass with a substantial portion of the nitrogen these components need to grow.
Frost seeding offers several important advantages
Sod disturbance is kept at a minimum, ideal for erodible areas.
Animals can access areas for grazing quicker than with conventionally tilled seedbeds.
Labor and equipment costs are minimal with frost seeding.
Frost seeding is not a guarantee, but to help ensure a successful stand, follow the below principles
Take soil tests. Soil tests taken before the fall should indicate whether fertilizer is needed to support the planned legumes.
Graze or clip the existing stand the previous fall to reduce the amount of thatch present. Intentional “grazing abuse” provides openings in the grass for clover emergence and sets back the grass the following spring just enough to allow the clover to further establish.
The freeze/thaw action in winter/early spring, along with spring rains, incorporates broadcasted legume seed. Frost seed mid-February through late March/April before frost leaves the ground, whether there is snow or not.
Following seeding, the area can be grazed as the trampling action of hooves will help incorporate the seed, as well as reduce the competition between existing growth and new seedlings. However, do not overgraze until the legumes have become established.
Remove cattle from the pasture before clover seedlings emerge. Bring them back once grasses are 8-12” tall. Some clover could be lost during this time, but these sacrificed seedlings are less than what we’d lose to competition if grasses aren’t grazed.
Most adapted forage legume species are suitable for frost seeding
Red clover is used most often because of its excellent seedling vigor.
White clover, birdsfoot trefoil, and alfalfa also work. Alfalfa should not be used if the existing pasture contains alfalfa due to alfalfa autotoxicity.