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 and ozone, on soybean and corn.
1b. Approach (from AD-416)
FACE technology is used to elevate and control levels of atmospheric carbon dioxide ozone. Canopy energy balance technologies are used to measure evapotranspiration and canopy temperature, capacitance probes and soil access tubes are used to measure soil moisture profiles, and a fully instrumented weather station monitors all aspects of weather at the research site.
3. Progress Report
This year a replicated full factorial drought by elevated CO2 interaction experiment was initiated. 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. Research activities were monitored by the ADODR by annual written reports and monthly meetings with the project participants.