Give a brief description of soil composition or the layers of soil?
Soil can be classified into 4 major layers. They are:
Horizon O
Horizon A
Horizon B
Horizon C
Horizon O refers to the upper layer of soil, nearest the surface. It is commonly known as topsoil. This layer includes organic litter, such as fallen leaves and twigs. The litter helps prevent erosion, holds moisture, and decays to form a very rich soil known as humus.
Horizon A is the layer below Horizon O. Litter is not present in horizon A and therefore there is much less humus. It consists of subsoil with sand, silt and clay.
Horizon B is below Horizon A. Horizon B consists mostly of weatherized big rocks. This solid rock gives rise to the horizons above it.
Horizon C is found below Horizon B and consists of parent rock.