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 was the 2nd year of a replicated full factorial drought by elevated CO2 interaction experiment. 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. As in the previous year of this experiment we assessed photosynthetic carbon assimilation, water use, and water status. This growing season mini-rhizotrons were added to the experimental design to monitor the dynamics of root growth and hydrolytic conductivity measurements were added to explore treatment effects on the water transport pathway through the plants. Research activities were monitored by the ADODR by annual written reports and monthly meetings with the project participants.