MADISON, WI, July 12th, 2010 While scientists have conducted numerous studies on production of biomass from biofuel crops, such as switchgrass, no one has yet compiled this information to evaluate the response of biomass yield to soils, climate, and crop management across the United States.
A team of researchers from Oak Ridge National Laboratory and Dartmouth College published just such a study in the July-August 2010 Agronomy Journal, published by the American Society of Agronomy. The researchers used peer-reviewed publications to evaluate switchgrass yield as it relates to site location, plot size, stand age, harvest frequency, fertilizer application, climate, and land quality. Switchgrass is one type of crop under consideration for use as a feedstock for advanced biofuels.
The scientists compiled a total of 1,190 biomass yield observations for both lowland and upland types of switchgrass grown from 39 field sites across the United States. Observations were pulled from 18 publications that reported results from field trials in 17 states, from Beeville, TX in the south, to Munich, ND in the Midwest, and Rock Springs, PA in the northeast.
Among the many factors examined, statistical analysis revealed that much of the variation in yield could be accounted for by variation in growing season precipitation, annual temperature, nitrogen fertilization, and they type of switchgrass.
Lowland switchgrass outperformed upland varieties at most locations, except at northern latitudes. Annual yields averaged 12.9 metric tons per hectare for lowland and 8.7 metric tons for upland ecotypes. Some field sites in Alabama, Texas and Oklahoma reported biomass yields greater than 28 metric tons per hectare using the lowland cultivars Kanlow and Alamo.
The research team did not observe any bias for higher yields associated with experimental plot size, row spacing, or with preferential establishment of stands on high quality lands
|Contact: Sara Uttech|
American Society of Agronomy