With nitrogen prices fluctuating between 60 and 90 cents per pound, frost-seeding white clover into pastures now could be a good way for farmers to add nitrogen and improve forage quality while reducing expensive fertilizer inputs.
“Frost-seeding involves surface application of seed, which is worked into the soil surface by winter rains and snow,” said Kent Messick, chief of field services with the North Carolina Department of Agriculture and Consumer Services’ Agronomic Division. “For the seed to be worked into the soil, it needs to be done very soon, so the catch is to find out if your pasture has the nutritional elements to make frost-seeding effective.”
A recent soil test report from the NCDA&CS Agronomic Division will provide the nutritional information necessary to determine whether a pasture is suitable for clover. There is not time to complete a new soil test, Messick said.
Soil pH is the most critical component because clover thrives at a pH of 6.0 to 6.5. For fields with a current pH of 5.5 or less, an immediate lime application will probably not work quickly enough to make the soil suitable for planting clover this season.
If soil pH is within the acceptable range, the next step is to consult with an NCDA&CS regional agronomist about the need to add phosphorus or potassium, based on your most recent soil test report. Current pasture crop, soil type, date of the soil report and any subsequent fertilizer applications will all be relevant factors to consider.
Once pH and nutrient levels are determined to be favorable for clover, success will depend primarily on the availability of moisture and implementation of good management practices. For best results, select improved, intermediate- to large-type ladino clovers. They are more productive than most native white clovers.
Grazing should be withheld until the clover is sufficiently established. If clover has not been present in the pasture for many years, inoculation of the seed with Rhizobium bacteria is advised. Several varieties are available pre-inoculated. To manage grass competition, do not apply nitrogen fertilizer or manures to pastures where you are trying to establish clover.
NCDA&CS regional agronomists are available statewide to offer advice about nutrient management, sample collection and interpretation of agronomic reports. For contact information, visit www.ncagr.gov/agronomi/rahome.htm or call the Agronomic Division at (919) 733-2655.