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Title: EVALUATION OF SWITCHGRASS AS A SUSTAINABLE BIOENERGY CROP IN TEXAS

Author
item SANDERSON, MATT - TEXAS A&M U STEPHENVILLE
item HUSSEY, MARK - TX A&M U COLLEGE STATION
item OCUMPAUGH, WILLIAM - TEXAS A&M UNV BEEVILLE
item Tischler, Charles
item READ, JAME - TEXAS A&M UNV DALLAS
item REED, RODERICK - TEXAS TECH UNV LUBBOCK

Submitted to: Biomass Conference of the Americas Proceedings and Abstracts
Publication Type: Proceedings
Publication Acceptance Date: 1/11/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: Switchgrass is a perennial, warm-season native forage grass. This grass has been selected by the U.S. Department of Energy as a model plant in studies to determine how much total plant mass (biomass) can be produced per acre for use as a fuel or as a starting material for producing liquid fuels. In 1992, Oak Ridge National Laboratory selected Texas A&M University and the Texas Agricultural Experiment Station as one of three regional centers to conduct studies designed to improve the establishment and yield of switchgrass. Results indicated that a variety called Alamo is the best-yielding switchgrass of any which are adapted to Texas. Alamo switchgrass responds to nitrogen fertilization with greatly improved yields. It does not always respond to phosphorous fertilization. Changing the spacing between rows does not greatly change total yields. Experiments designed to determine how many times per year Alamo switchgrass should be harvested have indicated that frequent harvests lead to lower total yields. Also, progress has also been made in developing Alamo switchgrass populations with characteristics which should improve seedling establishment.

Technical Abstract: Switchgrass (Panicum virgatum L.) has been selected as a model herbaceous biomass feedstock by the U.S. Department of Energy. Texas A&M University/The Texas Agricultural Experiment Station was selected as one of three Regional Switchgrass Cultivar and Management Testing Centers in 1992 by Oak Ridge National Laboratory. Research in Texas encompasses: (1) evaluating switchgrass germplasm at six locations;(2) determining defoliation, fertility, and row spacing response of switchgrass; (3) selecting for differential crown node elevation and reduced seed dormancy in Alamo switchgrass; (4) basic studies on switchgrass morphology; and (5) response of switchgrass to land application of municipal and agricultural wastes. Research locations span a north-south range of 725 km. We report on results from Objective 1 in this paper. Alamo switchgrass has been one of the best performing cultivars at all locations with yields ranging from 8 to 20 Mg of dry biomass ha**-1. Increased production of Alamo in response to N fertilizer was quadratic at Stephenville and linear at Beeville to the highest N rate used of 200 kg ha**-1. There was a small response to 20 kg ha**-1 of P2O5 in 1992 at Stephenville, but no response in later years or at Beeville. Row spacing has not had a consistent effect on switchgrass yield. Harvest frequency studies have shown that total seasonal yields are decreased as harvest frequency increases. We have made progress in selecting populations for enhanced and reduced crown node (subcoleoptile internode) elevation and in reduced post harvest seed dormancy.