Complement bermudagrass with alfalfa

By Mike Rankin

Alfalfa has not been a “go to” forage in the South for a long time, but for many forage producers that line of thinking is starting to change. A combination of recent research and extension efforts along with grower success are fueling alfalfa’s Southern resurgence.

“Alfalfa, interseeded into bermudagrass, will boost the relative forage quality (RFQ) of harvested forage by 25 to 40 units,” noted Jennifer Tucker, an assistant professor with the University of Georgia. “Adding legumes such as alfalfa to grass will both improve forage quality and enhance animal performance.”

Tucker and Kim Mullenix, an extension beef specialist with Auburn University, are part of a research team who are in the process of evaluating best management practices for alfalfa-bermudagrass mixtures in the Southeast. They recently discussed the practice on a Southeast Cattle Advisor webinar.

When interseeding alfalfa into existing bermudagrass stands, Tucker made the following recommendations based on her experience and existing research.

1. Before seeding, submit a soil sample for testing and ensure that the soil pH is 6.5 or greater. Below 1 foot in the soil profile, the pH should be greater than 5.5. Also make sure soil phosphorus and potassium are adequate to support alfalfa establishment and subsequent plant growth.

2. Plan to seed alfalfa in the fall. In the South’s Piedmont region, target September 15 to October 15. In the Coastal Plains, the optimum time frame is October 15 to November 15.

3. Ideally, suppress bermudagrass growth with a low rate of glyphosate or Gramoxone before seeding alfalfa.

4. Seed when there is adequate soil moisture and when air temperatures are sufficiently low enough to slow bermudagrass growth.

5. Plant seeds using a 14- to 15-inch row spacing. For most no-till drills, this means plugging every other hole in the seed box. Cut seeding rates to half the normal, or about 12 to 14 pounds of seed per acre.

6. Drill seeds 1/4- to 1/2-inch deep. It’s best to stay on the shallower end of that range.

7. Once established, monitor for insects, weeds, and diseases; use control measures as needed.

“During the first year after establishment, don’t take the first cutting until alfalfa reaches the early to mid-bloom,” Mullenix recommended. “This gives the plants a chance to establish a good root system. Following the first cutting, stands can be cut every 28 to 40 days based on desired forage quality. Try to cut before the bermudagrass begins heading,” she added.

To speed drying, Mullenix recommends using a mower-conditioner to help crush stems. She also reminded webinar participants to rake when the forage moisture is about 40 percent; this will help prevent leaf loss.

“One of the reasons that alfalfa has become more popular in the Southeast is that varieties have been developed specifically for the region,” Mullenix said. “In addition to improved forage quality, alfalfa that is interseeded into bermudagrass extends the forage production season and improves overall forage yield.”

Mullenix noted that there would be an “ebb and flow” to production. “Early and late in the season, expect alfalfa to dominate the stand. During the hot summer months, expect to see more bermudagrass,” she said.

The average stand life for alfalfa is three to five years. To enhance persistence, the beef specialist suggested that producers not cut or graze stands too short and give them adequate time between cuttings.

“Take the last cutting about 30 days prior to first frost,” Mullenix said. “This will help ensure that plants have adequate root carbohydrate reserves before winter.”

Finally, Mullenix noted that they are still in the process of evaluating grazing strategies for alfalfa-bermudagrass mixtures. A three-state, multilocation grazing study is currently underway in Alabama, Georgia, and Florida.