The 2008 Joint Meeting of the Society for Range Management and the America Forage and Grassland Council. |
Wednesday, January 30, 2008 - 9:40 AM
Seeding Rate Effect On Establishment And Yield Of Alfalfa In Bermudagrass Sod
John A. Jennings1, Wayne K. Coblentz2, Zelpha B. Johnson1, and J. Vaughn Skinner3. (1) Animal Science, University of Arkansas, P.O. Box 391, 2301 S. University, Little Rock, AR 72203, (2) U. S. Dairy Forage Research Center, 1925 LINDEN DR W, MADISON, WI 53706, (3) Agricultural Experiment Station, University of Arkansas, PTSC 115, University of Arkansas, Fayetteville, AR 72701
Establishing alfalfa often requires field conversion from another forage species. Planting alfalfa into bermudagrass sod reduces risk of forage loss because bermudagrass would remain if alfalfa was not successfully established. Previous Arkansas experiments on establishing alfalfa in bermudagrass sod at seeding rates of 18-20 lbs per acre have shown inconsistent results due to adverse weather and soil moisture conditions. This study was conducted to determine if increasing seeding rate would improve establishment success of alfalfa no-till planted into bermudagrass sod. Alfalfa was seeded into mowed bermudagrass sod at 10, 20, 30, 40 lbs per acre in October of 2003 and 2004. Plant density was determined after emergence and after the first year. Stem counts and dry matter yield were determined at each harvest. Alfalfa plant and stem counts were generally lower (P<0.05) for the 10 lb seeding rate and highest for the 30 and 40 lb rates. Percent alfalfa coverage in the row in 2005 ranged from 33 to 48 percent for the 10 lb rate, but was greater than 70% for the 30 and 40 lb seeding rates. Bermudagrass stand was suppressed in all treatments particularly at alfalfa seeding rates above 10 lbs per acre. Total dry matter yield ranged from 12,475 to 15,403 lbs per acre for the 2003 seeding and 5,602 – 6,907 lbs per acre for the 2004 seeding. Yield was generally not different among treatments except for the first and last harvest of the 2004 seeding when yield was highest for the 30 lb seeding rate. Lack of consistent yield response across seeding rates indicates the plasticity of alfalfa and bermudagrass growth between low and high alfalfa plant densities. Results suggest that a minimum alfalfa seeding rate should be 20 lbs per acre, but higher rates improve plant and stem density for potential stand persistence.