Frost Seeding Legumes

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There is no doubt that the drought of 2012 and the weather extremes of 2013 have stressed pastures. Maintaining a productive stand in your pasture is crucial for animal performance, holding feed costs down, and making the most of the productive soil you have invested in.

Frost seeding clover is a good strategy to deploy to fill in wholes and weak stand areas in pastures. Red clover is the most popular specie to add via frost seeding. Two major characteristics support it's popularity. It has very good seeding vigor and seed size is large enough it can be accurately applied via frost seeding.

White clover is also a good choice for pastures that will be grazed. It will not provide much to a hay crop as it grows closer to the ground. White clover seed is much smaller in size, thus accurately applying seed is more challenging. Mixing it with field lime or red clover will allow for better seeding rates across a pasture.

When seeding legumes it is important to take a look at soil pH. If your soils are more acidic (pH below 6) then establishing legumes will come with limited success. Many pastures that have been overgrazed, abused, or used for hay production fall into this category. Overgrazed pastures need field lime applied to bring the pH back up into a suitable window for legume establishment.

Overgrazing pastures in the fall actually helps with seed-soil contact of frost seeded legumes. Many times pastures with too much residual are poor candidates for frost seeding. I recommend harrowing these pastures to better incorporate the seed. In overgrazed pastures, the freeze-thaw of the spring weather along with some timely snows or slow rains can help incorporate the seed.

Seeding rate can vary. If you have never frost seeded clover before I would suggest 10 lbs. per acre of red clover. If you are mixing white clover in at 1 lb. per acre you can bring that down to 6 or 7 lbs of red clover per acre. If you are annually frost seeding clover 3-5 lbs per acre may be sufficient. No matter what rate you seed, be sure the soil and pasture conditions are managed to maximize your seeding.

A few tips for frost seeding legumes:
-Do not add N fertilizer (will stimulate the grass species and increase competition for the new seeding)
-Add field lime to bring soil pH up
-Incorporate the seed into the soil with a harrow or animal foot traffic (make sure to remove animals soon after)
-Apply a strong rate (at least 5 lbs/acre)
-Use inoculated seed from a reputable source

I like frost-seeding legumes for many reasons:
-Low cost
-Adds diversity to the stand
-A 30% legume stand can add up to 100 lbs. of N to a pasture
-Helps dilute fescue and the endophyte issues with KY31
-Fills in weak stand spots in pastures thus helping combat weed pressure
-Will be more active and productive in the summer slump than cool season grasses