Frost seeding of legumes in February and early March can be used to improve pasture quality and yield. The freezing and thawing of late winter and early spring can provide for good legume seed and soil contact and germination. The following steps will help to ensure frost seeding success.
Site selection. Choose a pasture that is well drained and has been closely grazed. A thin sod will likely reduce competition and allow for seed to soil contact.
In addition, a southeasterly slope will receive more sunlight and favor legume growth. Animals will also help to trample seed for better soil contact. However, remove animals when germination of the seeded legume begins.
Soil pH should be 5.5 or above, with better legume growth at soil pH levels above 6.0. A soil test should have been taken and phosphate and potash can be broadcast by mid-May.
Inoculate. If the legume plant being seeded does not currently exist in the pasture, inoculate legume seed with the appropriate strains of nitrogen-fixing bacteria.
Remember innoculants should be stored in a refrigerator from the time of purchase to use. The rhizobia bacteria can be killed at high temperatures. Also, check the expiration date on the inoculate package.
Grazing management. Allow newly seeded legume plants to grow. Do not overgraze newly seeded plants. Manage grass height so as to allow sunlight to reach clover plants.
Clover and other legumes are often the preferred forage species of grazing animals. For this reason rest periods between grazing may need to be adjusted to allow for adequate legume regrowth.
Apply needed phosphorus and potassium according to soil test recommendations. Use nitrogen in small and split applications, as excess nitrogen will likely cause grass to overcrowd and out-compete legume plants. A pasture composed of 35 percent legume may need no additional nitrogen.
Selection. Follow the following information on species selection and seeding rates per acre.
Red clover and birdsfoot trefoil: 6-8 pounds red clover and 3-4 pounds birdsfoot. This combination provides good legume compatibility for cattle.
Red clover and ladino: 6-8 pounds red clover and 2 pounds ladino. This combination will support grazing for both sheep and cattle.
Ladino: 3 pounds per acre provides for close grazing and tolerance to a slightly lower pH.
Changing pasture composition requires changing pasture management. If you continue to manage the same, you’ll keep getting what you’ve got.
For more information contact your local Extension Office.
(The author is an extension agent in Guernsey County and Ohio forage team co-leader.)