Clovers provide several benefits when they are used in pastures along with grass species. If the pasture species composition is 30 to 50% legumes research has showed us there is no benefit to adding additional nitrogen fertilizer. With current nitrogen prices in the 60 cents per pound range, the elimination of the need for commercial fertilizer can result in a savings of between $40 and $60 per acre per year based on nitrogen fertilizer recommendations for pastures and hayfields that are all grass.
Another benefit to having 30 to 50% of the pasture species legumes is that legumes will help fill in the “summer slump” that most cool season grasses have during the middle of summer. During this time frame legumes do not have the slowdow in growth that our common cool season grasses have. This provides growth that the animals can graze making for less acres or less need for supplemental feed for a given number of animals. A third benefit to including legumes in the pasture mix is that their presence increases the quality of the grazed feed because they are typically higher in nutritional value than grasses, particularly as the plants mature. This improved feed quality leads to better animal performance.
Ideally a farm would look at implementing a program where they would set up their pastures and permanent grass hayfields on a rotation where they would interseed 1/3 of them each year as the legumes should last at a sufficient level in the stand for three years.
A low cost method to get clovers into pastures is to frost seed this time of the year. Following are some considerations for pasture owners who may want to frost seed some clovers this spring.
Frost seeding is broadcasting forage seed on the ground surface while the ground is still frozen in the spring. Farmers have reported that frost seeding works 50 to 70 % of the time. Some feel it is worth it because of the cost saving from not needing a seeder. While frost seeding is a less expensive method of seeding forages than using seeders, it is also riskier than seeding with a drill because seed-soil contact is less good. Frost seeding can result in increased legume percentage but not in uniform stands of the seeded forage. Frost seeding may be acceptable for pasture improvement but not for establishing hay fields.
If a pasture has weed problems, get the weeds under control first. Herbicides used to control the broadleaf weeds will kill desirable legumes too.