Start Date: May 27, 2005
End Date: May 20, 2010
Crop and weed species will be grown at the current ambient concentration of carbon dioxide and at 1.5 times that concentration in field plots, using open top chambers, and in growth cabinets. Changes in gene expression, physiology, and the growth of crops will examined at ambient and elevated concentrations of carbon dioxide in combination with high temperature stress, drought stress, and competition from weeds. Soybeans, common beans, spring wheat, oats and some weed species will be examined for genotypic differences in responsiveness to carbon dioxide concentration. Invasive and non-invasive weed species will be compared for responses to rising atmospheric carbon dioxide. Impacts of elevated carbon dioxide on yield responses to nitrogen fertilizer will be determined in a corn, wheat, soybean crop rotation system. The effect of elevated carbon dioxide on soil carbon sequestration will be examined in two no-till cropping systems.