Submitted to: Agronomy Abstracts
Publication Type: Abstract only
Publication Acceptance Date: 9/1/2003
Publication Date: 10/1/2003
Citation: Berdahl, J.D., Singh, A., Hendrickson, J.R. 2003. Survival of hay-type and grazing-tolerant alfalfa populations in season-long and rotational grazing systems for beef. Agronomy Abstracts. Interpretive Summary:
Technical Abstract: Poor longevity is a major factor reducing the use of alfalfa (Medicago spp.) for grazing in the northern Great Plains. Persistence of 23 alfalfa cultivars and experimental strains in pure stands and binary mixtures with meadow bromegrass (Bromus riparius Rehm.) was evaluated at Mandan, ND under continuous and rotational grazing treatments with yearling steers. Soil was a Wilton silt loam (fine-silty, mixed, superactive, frigid Pachic Haplustolls). Annual precipitation was 127, 145, and 133% of a 120-yr average for the 3 yr that grazing occurred. Continuous, season-long grazing began in early June of each year when 'Beaver' alfalfa reached the bud stage of development and continued until Oct. 1. Rotationally grazed treatments, mob-grazed until alfalfa height was reduced to 7 to 10 cm, were initiated whenever Beaver reached the bud stage, resulting in 3 to 4 grazing events per season. After 3 grazing seasons, alfalfa survival measured in the following spring averaged 49% in pure stands and 45% in grass-alfalfa mixtures under continuous grazing and 83 and 78% for pure stands and mixtures, respectively, under rotational grazing. Survival of the top four entries under continuous, season-long grazing averaged 80%. Plant traits that contributed to winter survival were essential for long-term persistence.