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United States Department of Agriculture

Agricultural Research Service

Title: Establishment Stand Thresholds for Switchgrass Grown As a Bioenergy Crop

Authors
item Schmer, Marty
item Vogel, Kenneth
item Mitchell, Robert
item Moser, L. - UNI OF NE
item Eskridge, K. - UNI OF NE

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 24, 2005
Publication Date: January 14, 2006
Citation: Schmer, M.R., Vogel, K.P., Mitchell, R., Moser, L.E., Eskridge, K.M. 2006. Establishment stand thresholds for switchgrass grown as a bioenergy crop. Crop Science 46:157-161.

Interpretive Summary: Switchgrass, a native prairie grass, is a potential bioenergy crop. Field scale trials in the Northern Great Plains states of Nebraska, South Dakota, and North Dakota were used to determine threshold or minimal switchgrass stands for switchgrass when grown as a biomass energy crop. Results from the three-state evaluation area indicate that an establishment year stand frequency levels of 40% or greater as determined by a frequency grid can be considered an establishment year stand threshold for successful establishment and subsequent post-establishment year biomass yields for switchgrass grown as a bioenergy crop in the Northern Great Plains. An establishment year stand frequency of 25% would be adequate for a switchgrass conservation planting for which no harvests would be planned for several years.

Technical Abstract: Switchgrass (Panicum virgatum L.) is a warm-season (C4) perennial grass and a potential bioenergy crop. On-farm switchgrass field scale trials, which were initiated to obtain economic production information for switchgrass grown as a bioenergy crop in the Northern Plains, provided field sites to determine the relationships between establishment year stand and post-establishment year stands and biomass yields both within and across fields. An additional objective was to determine if a stand threshold exists for switchgrass grown as a biomass energy crop at the field scale. Switchgrass was seeded in 10 cropland fields, ranging in size from 3 to 9.5 ha, in Nebraska, South Dakota, and North Dakota in 2000 and 2001. The fields were selected to be representative of their region and be eligible for the Conservation Reserve Program. Twelve sites within each field were geo-referenced, and switchgrass stand frequency was measured at each sample site. Biomass yields were estimated in late summer at the same within field sites using a clipped quadrat. Fields with low initial switchgrass stand frequencies showed a linear relationship between initial stands and second year switchgrass stands and biomass yields. Results from the three-state evaluation area indicate that an establishment year stand frequency levels of 40% or greater as determined by a frequency grid can be considered an establishment year stand threshold for successful establishment and subsequent post-planting year biomass yields for switchgrass grown as a bioenergy crop in the Northern Great Plains, USA. An establishment year stand frequency of 25% would be adequate for a switchgrass conservation planting for which no harvests would be planned for several years.

Last Modified: 11/26/2014