Apes in a box: Soil profile notes -a cross sectional soil layers from the surface of the soil of the soil down to the bedrock -o horizon: the top is partially COMPLETELY undecomposed plant -A Horizon: uppermost layer of the soil,has decomposing organic material known as hummus -B horizon: known as subsoil,plant roots penetrate this area ,more INORGANIC material c horizon: made up of parent material in the soil, large amounts of unbroken pieces of rock, weathered to produce inorganic components of soil -