Around Area Farms
Frost seeding can be an effective, low-cost method to improve pastures. Frost seeding is used to introduce new forage species into an existing sod or maintain the current forage composition of pastures.
The idea behind frost seeding is that alternating freezing and thawing, along with spring rains, will incorporate the broadcast seed into the soil surface. Seeding on top of snow is acceptable if the depth is not too great. The risk of seeding on top of snow is that a rapid meltdown may result in runoff of water and seed. In Indiana, most frost seeding is done during March.
Be certain to inoculate legume seeds prior to seeding. Bacterial inoculant is specific for each legume species. For example, alfalfa inoculant is not effective on red clover. If you do not inoculate, the legumes will most likely fail to grow rhizobia nodules on their roots, so they will not be able to fix nitrogen.
To be successful, good seed-soil contact is needed. Most of the intensive grazers who frost seed pastures allow the cattle to graze the pasture close to the soil surface in the fall before the seeding. Clipping pastures close to the soil surface can accomplish the same thing. If the pasture has heavy sod, a light disking can tear up the stand just enough to expose some soil. The best results are obtained in forage stands of non-sod-forming species without a thatch barrier.
There are many excellent tools for making broadcast frost seedings. These include seeders that mount onto ATVs and tractor three-point hitch-mounted seeders. Conventional roller and grain drill seeders can be used but will require more trips across pastures. When using spinner-type seeders, be sure to determine the effective seeding width for each seed type or mixture. This will vary between species.
After frost seeding, the newly planted seed will need a little help if it is going to survive. Reduce the competition from the established plants by frequent grazing or machine harvests.
In our area, red clover is frequently used to improve grass pastures. I know people with pure alfalfa stands who have added orchard grass when they convert a hay field to a grazing pasture. Some grasses such as perennial or annual ryegrass and smooth bromegrass can be successfully frost seeded with proper management.
Jeff Burbrink is an Extension educator in agriculture and natural resources. Write to him at 17746 E. C.R. 34, Goshen, IN 46528; call 533-0554; or fax 533-0254.