Subject:
Soil: The Base of Life Major Layers Found in Soil a.Soil Horizons Series of zones with distinct texture and composition. Soil Profile is a cross-sectional view Most soils have at least 3 horizons b. Horizon O (Top Layer) 1. Consists of freshly fallen and partially decomposed leaves, twigs etc? 2. Appears Brown or Black, Humus ? Sticky, brown residue of partially decomposed organic material. c. Horizon A (Topsoil Layer) 1. Partially decomposed matter ?humus? and topsoil. 2. Most roots and organic matter are found in Horizon A and O 3. Horizon A and O team with bacteria, fungi, earthworms, insects ? create food web. 4. Color of soil tells a lot ? brown and black = nitrogen rich - Gray, Yellow, Red low inorganic matter. d. Horizon B (Subsoil)
