Marcus M. Eichhorn Jr. and Bradley C. Venuto

In the Coastal Plain of north Louisiana, pastures of annual ryegrass and cereal rye, alone or in combination, are made in late summer and fall to reduce dairy and beef cattle winter supplemental ration requirements and to enhance overall herd performance. Prepared seedbeds are planted to provide grazing on the earliest possible date. Bermudagrass sods are planted later, when competition from sods for soil moisture and plant nutrients is at lowest levels.

Because information was limited on the comparative performances of annual ryegrass and cereal rye plantings made in prepared seedbeds and bermudagrass sods, a study was conducted at the Hill Farm Research Station. The objectives were to determine the relative annual yield performances of annual ryegrass and cereal rye when planted alone or in combination into either a prepared seedbed or bermudagrass sod and to provide useful information to the Louisiana Cooperative Extension Service for making recommendations to livestock producers that will optimize forage production from their intended fall plantings.

Materials and methods

Experiments were conducted for three consecutive growing seasons, 1994-95 through 1996-97, with Marshall annual ryegrass and Maton cereal rye. Each year, starter fertilizer at 600 pounds of 4-16-32 (N-P2O5-K2O) per acre was broadcast on the soil surface and incorporated to a 3-inch depth before planting seed in prepared seedbeds.

On Coastal bermudagrass sods, starter fertilizer at a similar rate also was broadcast on the surface after all standing forage was cut to a 2-inch stubble height and removed from the area intended for planting. Marshall ryegrass and Maton rye seeding rates were 30 pounds and 90 pounds per acre, respectively, when planted alone or in combination. When planted alone in prepared seedbeds, ryegrass and cereal rye seed were drill-planted at 1/2-inch and 1-inch soil depth, respectively. Planted in combination, cereal rye seed was drill-planted and ryegrass seed was broadcast afterward on the surface of plots. For plantings made in Coastal bermudagrass sods, ryegrass seed was broadcast on the surface of plots when planted alone or after the cereal rye seed was sod-seeded. Cereal rye was sodseeded at a 1-inch soil depth when planted alone or in combination with annual ryegrass. Averaged across years, prepared seedbeds were planted on October 5, and Coastal bermudagrass sods were planted on October 19.

Post-establishment fertilization practices and harvest frequencies were similar each year for prepared seedbeds and bermudagrass sods. Fertilizer, 30-0- 0-8 (N-P2O5-K2O-S) at 300 pounds per acre, was broadcast on the surface of the plots in mid-November, and fertilizer, 17-5-20-5 at 588 pounds per acre, was applied after the February and March harvests. Mean harvest dates across years were December 10, January 10, February 6, March 6, April 5 and May 18.

Results and discussion

Planting methods had a considerable effect on annual ryegrass and cereal rye forage production (Table 1). When data were subjected to contrast analysis, from December to March, drill-planted annual ryegrass in prepared seedbeds out-yielded broadcast-seeded plantings on bermudagrass sod. Drill-planted cereal rye in prepared seedbeds outyielded sod-seeded cereal rye for most of the late fall and winter growing season. Drill-planted cereal rye over-seeded with annual ryegrass on prepared seedbeds produced higher forage yields throughout the growing season than sod-seeded cereal rye over-seeded with annual ryegrass. Across all planting methods (broadcast, drill-seeded and sod-seeded) and seedbeds (prepared and bermudagrass sod), yields for annual ryegrass and cereal rye were greatest during March and April.

Across the growing season, drillplanted annual ryegrass on prepared seedbeds out-yielded broadcast plantings on bermudagrass sods by about 50 percent. Because mature beef and dairy cattle require about 25 pounds of forage dry matter per day for maintenance, establishing ryegrass on prepared seedbeds had the potential to provide an additional 86 days of animal grazing. Yield for drill-planted cereal rye in prepared seedbed was not different from sod-seeded cereal rye. Both methods of establishing cereal rye had the potential to provide an average 184 days of grazing.

Where annual ryegrass seed was broadcast over drill-planted cereal rye in prepared seedbeds, the yield was 50 percent higher than that of annual ryegrass seed broadcast on sod-seeded cereal rye. Potential for grazing was 99 days longer for ryegrass and cereal rye established in the prepared seedbed. Across all planting methods and seedbeds, drill-planted cereal rye in a prepared seedbed over-seeded with a broadcast application of annual ryegrass seed provided highest forage yield with highest potential animal days of grazing.

These findings will be helpful to livestock producers across the Coastal Plain of north Louisiana who intend to plant annual ryegrass and cereal rye, alone or in combination, in the fall into either prepared seedbeds or bermudagrass sods. Cereal rye-ryegrass mixtures on prepared seedbeds will provide the most forage.

Marcus M. Eichhorn Jr., Professor, Hill Farm Research Station, Homer, La., and Bradley C. Venuto, Assistant Professor, Department of Agronomy, LSU Agricultural Center, Baton Rouge, La.

(This article was published in the winter 1999 issue of Louisiana Agriculture.)