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 4th season for the fully replicated 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 experiments have revealed that growth at elevated CO2 substantially reduces evapotranspiration in soybean and this reflected in improved soil moisture reserves but there is considerable interannual variability in the interaction that is driven by seasonal climatic conditions. Specifically, in years in which precipitation is low, the increase in leaf area driven by the stimulation of photosynthesis by elevated [CO2] can completely offset the conservation of soil moisture due to improved water use efficiency. Research activities were monitored by the ADODR by annual written reports and monthly meetings with the project participants.