A short time-lapse video of maize growing and the measured cumulative CO2-C exchange from eddy covariance.
Down is a loss and up is a gain. There are initial C losses before maize growth is established and then gains as the maize grows. The net C balance will also need to take into account removal of C with harvest.
The animation has been provided by University of Waikato's Louis Schipper and created by University of Waikato's Aaron Wall as part of the PhD he is doing alongside his role in the NZAGRC programme. More information on this work can be found at http://www.nzagrc.org.nz/soil-carbon.html