Digging a trench into the ground exposes
a side view of soil. This view of soil is called a soil profile.
Soil profiles often reveal layers below ground with slightly
- The topsoil, also called the A horizon, contains organic
material, or humus. Humus forms from decayed plant and animal
- Below the topsoil is the subsoil, also called the B horizon.
The subsoil contains clay and iron oxides washed from the
- The bottom layer, also called the C horizon, is composed
of rock fragments of weathered parent material.
the drawing tool to draw lines across this soil profile, separating
the soil into three layers: the topsoil, the subsoil, and
the weathered parent material.