In 2010-2011 samples were analyzed for total carbon only. In 2014 some samples were analyzed for inorganic as well as organic carbon. You may mouse over bars to see numeric values for each section.
Sampling was done with a slotted probe cutting continuous cores, with segmentation at indicated intervals below the soil surface. Samples were composited from 8 cores, taken in grid patterns according to the method described in Measuring Soil Carbon Change: A flexible, practical, local method