OBJECTIVE FORESTRY

Detailed explanation-1: -Soil Horizons are the distinct layers of a soil profile. They are divided into these layers, referred to as “Master Horizons” (from top to bottom): O Horizon, A Horizon, E Horizon, B Horizon, C Horizon, and R Horizon.

Detailed explanation-2: -Soils are named and classified based on their horizons. The soil profile has four distinct layers: 1) O horizon; 2) A horizon; 3) B horizon, or subsoil; and 4) C horizon, or soil base (Figure 31.2. 2).

Detailed explanation-3: -The simplest soils have three horizons: topsoil (A horizon), subsoil (B horizon), and C horizon.

Detailed explanation-4: -Most soils contain a B horizon except young soils or soils highly resistant to weathering (e.g., Entisols) in which an A horizon is directly underlain by a C horizon, an AC horizon or bedrock. Andisols, Gelisols, Histosols, Mollisols, and Vertisols may also lack a B horizon.