They are formed through pedogenesis, and have layers called horizons.
Ammonium acetate extraction can be used to measure the cation exchange capacity of these materials. The composition of these materials distinguishes edaphic communities. They are formed through pedogenesis, and have layers called horizons. These materials contain decayed organic matter called humus, and are classified by composition of silt, sand, and clay. For 10 points, name this kind of material formed from weathered rock, in which plants grow.
Ammonium acetate extraction can be used to measure the cation exchange capacity of these materials.
soil [prompt on "dirt" or "regolith"]