1a.Objectives (from AD-416):
The objective of this cooperative project is to maintain a FACE research site for investigating the effects of global change, including increased levels of atmospheric carbon dioxide, drought, temperature and ozone on soybean and corn.
1b.Approach (from AD-416):
Free Air Concentration Enrichment (FACE) technology is used to mimic under field conditions atmospheric concentrations of carbon dioxide and ozone predicted for 2050. Crop canopy heating using arrays of infrared heaters are used in conjunction with FACE to mimic the effects of global warming under field conditions.
Drought stress is the most important factor limiting crop photosynthesis and yield. The interaction between drought and elevated [CO2] is not additive and the consequences of simultaneously greater drought and elevated [CO2] for crop production are unclear. The experimental design is a completely randomized block design (n=4), with [CO2] as a between-plot factor and drought as a split-plot factor. Starting immediately after planting and continuing throughout the growing season, nighttime rainfall is intercepted by a retractable awning covering the "dry" treatment plot. This will simulate the reduction in rainfall typically seen in drought years for this region. Throughout the current growing season we assessed photosynthetic carbon assimilation, water use, and water status. The mechanism of response is being investigated through measurements of transcript profiles and biochemistry.