Wednesday, November 15, 2006

Hay vs. Biomass Harvest Management Effects on Forage Quality Traits of Alfalfa Stems.

JoAnn Swinton Lamb, Univ. of Minnesota, USDA-ARS, St. Paul, MN 55108, Heathcliffe Riday, Iowa State University, US Dairy Forage Research Center, 1925 Linden Drive West, Madison, WI 53706, Hans Jung, Univ of Minnesota, USDA-ARS, St. Paul, MN 55108, and Craig Sheaffer, Dept. of Agronomy and Plant Genetics, University of Minnesota, 411 Borlaug Hall, 1991 Buford Circle, St. Paul, MN 55108.

Alfalfa (Medicago sativa) has been proposed as a cellulosic source for biofuel or ethanol production. In an alfalfa biomass production system, leaves would be sold separately as an animal feed and stems would be processed to produce ethanol.  We have shown that decreasing plant density, harvesting at later maturity stages, and reducing harvest frequency (biomass production management) can substantially increase stem yield, and decreases harvest cost compared to management practices currently used in alfalfa hay production. Our objective was to compare experimental alfalfa biomass populations to commercially available high forage quality and non-lodging alfalfa cultivars under both hay and biomass management systems for both stem and leaf quality traits. Preliminary results showed that all alfalfa entries had greater amounts of stem glucose and total cell wall sugars under the biomass production system compared to the standard hay production system and that experimental alfalfa biomass populations produce more total cell wall sugar compared to commercially available cultivars.