Carbon Balance and Greenhouse Gases in Agricultural Systems
Concerns about the impact of rising atmospheric CO2 concentrations on global climate have inspired efforts to identify ways in which CO2 can be removed from the atmosphere, or sequestered. In this project we are examining various farming strategies that have been proposed to increase carbon storage in soils as organic matter. These include reduced tillage and modified cropping systems that include winter cover crops and perennial living mulch crops. The approach that we are using involves continuous measurement of surface/atmosphere CO2 exchange in neighboring fields with the same soil type, but differing farming practices. CO2 exchange and water use are measured by eddy covariance, using a sonic anemometer and open-path infrared gas analyzer.
Eddy covariance installation at Rosemount
One field is managed in conventional fashion for southern Minnesota, which means a corn/soybean rotation, with fall tillage consisting of chisel plowing. In adjacent fields we test alternative farming practices. Our field site at Rosemount, MN has been a part of the Ameriflux program since 2004. This is a network of research sites throughout North America where continuous measurements of CO2 and H2O exchange are made. The data are mare made available to researchers throughout the world for use in the development and testing of climate and crop models. A link to the data can be found on our biometeorology web site. We have also been active in measuring nitrous oxide (N2O) emissions from agricultural systems, using automated chambers.
Automated chambers for measuring CO2 and N2O emissions.