Digging is done primarily with trowels in the first several
layers, and then with shovels in the last layer as the hole gets deeper
and the goal is to dig all the way to bedrock or the C horizon. The
first layer to be removed is the forest floor. Oie and Oa are collected
in total, placed in separate bags and returned to the lab. After
the hole is measured to the top of the mineral soil, we dig 10 cm (the
0-10 cm mineral layer), checking the depth periodically to avoid digging
too far. The depth is measured and recorded for 10 cm, then we dig
another 10 cm (the 10-20 cm mineral layer). After the depth is recorded
for 20 cm, we typically dig to bedrock or C horizon (the 20+ cm mineral
layer).