Legumes are an essential part of a profitable grazing systems. Clover’s superpower is its ability to fix nitrogen from the air into a plant available form. After photosynthesis, nitrogen fixation is the second most important biochemical process on earth. Clover also increases forage quality and quantity and helps to manage tall fescue toxicosis.
Strong nitrogen cycles can develop in well managed pastures and hayfields. Nitrogen enters the system via imported hay and supplements, nitrogen fixation in legumes, and atmospheric deposition (minor amounts). Nitrogen leaves the system via volatilization, denitrification, leaching, runoff, and animal products removed. A cow-calf pair will consume approximately 280 lb N/year in the grasses and legumes they’re consuming of which 200 lbs is retained in the grassland ecosystem (Lory and Kallenbach, 1999).
Over time, clover stands in pastures can thin and will require reseeding. Although there are several approaches for reintroducing clover back into pastures, perhaps the simplest and most cost-effective is frost seeding. Frost seeding is accomplished by broadcasting clover seed onto existing pastures or hayfields in late winter and allowing the freezing and thawing cycles to incorporate the seed into the soil. It works best with red and white clover. Below you will find a few tips for enhancing frost seeding success.
· Control broadleaf weeds—Ideally, broadleaf weeds should be controlled prior to seeding legumes since most herbicides will damage clover seedlings. This is best accomplished by controlling weeds the season prior to renovation. See AGR-207 “Broadleaf Weeds of Kentucky Pastures” for information.
· Soil test and adjust fertility—Prior to frost seeding clover, soil test pastures and hayfields ]then lime and fertilize according to the soil test recommendations.
· Suppress sod and decrease residue—The existing sod must be suppressed and plant residue reduced prior to seeding to allow seed to reach the soil surface. This is best to accomplished by hard grazing in late fall and early winter.
· Ensure good soil-seed contact—Good soil-seed contact is required for seed germination and emergence. In frost seedings, this occurs when freeze and thaw cycles form cracks in the soil surface, often referred to as a honeycomb. Soil to seed contact can be enhanced by dragging pastures after broadcasting seed.
· Seed on proper date—Frost seeding is best accomplished in late winter (February).
· Use high-quality seed and adapted varieties— Choose clover varieties that have been tested in Kentucky. See current variety test results at the UK Forage website.
· Legume mixtures for Kentucky—In Kentucky, a good mixture for renovating pastures with is 6-8 lb/A of red clover, 1-2 lb/A of ladino or intermediate white clover. On rented farms or where soil fertility is marginal, adding 10-15 lb/A of annual lespedeza can be beneficial.
· Use correct seeding rate—Make sure to maintain and calibrate broadcast seeding equipment prior to planting (see video on KYForages YouTube) so as not to seed at too high or too low a rate.
· Inoculate legume seed—Most improved clover seed comes with a lime-based seed coating that contains the proper rhizobia bacteria, but if it’s bare seed make sure to inoculate. Store extra seed in a cool dry location and reinoculate after one year.
· Check seed distribution pattern—When using a spinner type spreader/seeder make sure and check your spreading pattern. In many cases small seeded forages are not thrown as far as you think. This can easily be done by driving over a large tarp or laying out buckets or cake pans perpendicular to your drive pattern and weighing the amount of seed in each.
· Use GPS guidance—Simple portable GPS guidance systems will allow you to maintain a consistent distance between passes and speed. Without GPS research has shown that many people waste seed by too much overlapping.
· Control post-seeding competition—Not controlling post-seeding competition is one of the most common causes of stand failures. One of the best management practices is to leave cattle on pastures that have been overseeded with clover until the clover seedlings have germinated. Then remove animals from the pasture and allow the clover to reach a height of 6-8 inches. Some producers flash graze the pasture once the grass starts to shade the clover seedlings. If the existing vegetation is not controlled, the new clover seedlings will be shaded out.
~ Excerpted from article by Chris Teutsch in Cow Country News (Jan. 2024)
The Alliance for Grassland Renewal 