Tuesday, November 14, 2006 - 10:35 AM

Design and performance of the SoyFACE Free-Air Concentration Enrichment system for elevation of Ozone.

Timothy A. Mies, Univ. of Illinois, AW-101 Turner Hall, 1102 S. Goodwin Ave, Urbana, IL 61801

SoyFACE (Soybean Free Air gas Concentration Enrichment) is a study of soybean response to projected atmospheric conditions in the year 2050.  Based on current projections, tropospheric ozone (O3) will increase about 25% over the next 50 years (IPCC 2001).  Current soybean yields in central Illinois are estimated to be depressed about 20% by current tropospheric O3 concentrations, and potentially could be decreased by 35% based on projected future concentrations.  SoyFACE allows the study of the effects of elevated CO2 and O3 levels in an open field setting without the artificial effects that can occur in an enclosed fumigation study. Fumigation into eight treatment rings with ozone has been repeated annually since 2003, allowing for a summarization of 3 years performance data.  This ozone fumigation system is based on the high pressure gas jets design currently used for CO2 fumigation (Miglietta et al.).  Ozone gas is produced from an oxygen feed gas passed through a high voltage electrical field.  The resultant gas is injected into a high pressure compressed air carrier gas for release into the treatment area.  Summary results will include an introduction to the design of the fumigation system, three years of performance data, and an evaluation of distribution of ozone within the treatment area.