Pot-grown Deltapine 51 cotton plants were exposed to three levels of ozone [24, 51, or 78 nL L^-1], carbon dioxide [ambient, +175 µL L^-1 or +350 µL L^-1], and soil nitrogen [0.2, 0.4, or 0.6 g urea-formaldehyde N per liter of soil mix, pH 6.4] in North Carolina State University open-top field chambers [volume = 17 m³_]. The 51 nL L^-1 ozone level approximated ambient ozone levels during 1996 in Raleigh, NC. The lowest ozone concentration was achieved through charcoal filtration of the air input. Ozone and carbon dioxide additions were made from 11 to 134 days after planting in 1995 and from 9 to 115 days after planting in 1996 when the experiment was terminated by Hurricane Fran.