By: Matthew Webb, County Extension Coordinator
As livestock producers, we may be missing an opportunity to improve pasture, animal health and our bottom line. If I told you there was one practice that could get you “cheap” nitrogen fertilizer, increase the yield and protein in your pasture, improve cow conception rates and calf performance for minimal cost, would you believe me? Adding clover to your pasture will do just that and you need to take advantage. Now is the time to think about overseeding pastures with clover.
Advantages of clovers: Clovers have a relationship with specific bacteria that allow nitrogen in the air to be “fixed” and made into plant available forms. Clovers may produce from 50-200 lbs N/acre in a year that can be used by associated grasses. As a result, pasture yield and distribution during the year is equal or better than pastures receiving moderate rates of nitrogen. A study in Kentucky showed that adding 6 lbs red clover/acre to tall fescue pasture increased yield by over 40% compared to fescue fertilized with 90 lb N/acre over a two-year period. Also, legumes have a high feed value so animal weight gains and conception rates are improved by 30-40% when grazing clover-grass pastures compared to grass-only pastures. A desirable mixture would be for a pasture to contain 30% legume. Note: There is a risk of bloat if pasture is over 50% clover.
Establishing clovers in pasture: Pastures that have come out of drought and winter can have some thin, open areas prime for weed invasion. Introducing clovers can aid in thickening up the pasture and compete with weeds. Our most adaptable clover species for our area include: white and red clovers and annual lespedeza. White clover is tolerant of grazing while red clover is a better producer, particularly in summer. Annual lespedeza is not a clover but is important as a warm season, non-bloating legume that provides forage during late summer when cool-season pastures are slumping. Also, it is tolerant of drought and poor soil fertility. An important note prior to seeding legumes, clover seed must be inoculated with specific bacteria in order for nitrogen-fixation to occur. Seed white clover at 2-3 lbs/acre, red clover at 4-6 lbs/acre, and annual lespedeza at 20-30 lbs/acre. Use the lower rates if you plan to plant a mix of the species. For hay fields, forego the white clover and annual lespedeza and use red clover at a rate of 8-10 lbs/acre. To maintain high yields, clover should be broadcast every 2 to 4 years.
A cheap option for establishing clovers is to “frost seed” clovers into pastures. Frost seeding is broadcasting seed on to pasture sod in late winter (Feb. 1 – April 1). Frost seeding works as seed becomes incorporated into soil by the natural freezing and thawing that occurs during those months. Animals tread in some seed by hoof action or you may use a chain harrow drag to improve the seed-to-soil contact. If you prolong until late spring, reduce the grass competition by grazing or apply herbicide in strips and use a no-till drill to establish clover more effectively. DO NOT plant any deeper than ¼ – ½ inch.
Does every pasture or field have to have clover presence? Not necessarily. Work completed in Arkansas suggests that white clover could be sown at higher rates in strips instead of sowing the whole field. Clover establishment and persistence was greater in strips versus sowing the whole field. Also, there was a savings in time, fuel and labor with the strip seeding method. In addition, there will be areas that need to be avoided to grow clover because of a lack of fertility or moisture conditions to maintain clover stands. Also, if weeds are problem, those areas may be treated for weed control. Options for maintaining clovers in grass stands are very limited when it comes to weed control.
Maintaining clovers in pasture: Legumes are a little more difficult to maintain than grasses. With the exception of white clover, legumes are sensitive to defoliation as they rely on carbohydrate stores in the roots for growth. For best persistence, rotate animals through pastures and begin grazing when pasture is 8-10 inches tall and graze down to 2 inches in a one-week period if possible. Allow a rest period of 3-6 weeks depending on growing conditions. If you do not have a means of rotating animals, try to keep grass height no higher than 4-5 inches as grasses can grow tall and shade out the clover. Conduct a soil test to determine appropriate fertilizer needs. Phosphate and potash levels need to be in the medium range as determined by a soil test. Soil pH should be 5.8-6.5. Nitrogen should not be applied as grasses will become more competitive and shade out legumes.
The cost of clovers: Clover seed cost will run about $20 to $35 per acre. Considering that a good stand of clover will fix an average of about 50 to 100 lbs N/acre per year and will persist for at least three years, this clover nitrogen could conservatively cost less than 12 cents to 24 cents per lb N. That is cheaper than commercial nitrogen. Also consider what was mentioned before, animal gains and conception rates will be increased. Clovers offer some advantages that are cost effective and worth trying.
