Question

What is the soil profile? Explain the characters of different soil horizons.

Answer 1

Horizon	Description
O-Horizon (Organic horizon) Humus SamacheerKalvi.Guru	It consists of fresh or partially decomposed organic matter. 01 - Freshly fallen leaves, twigs, flowers, and fruits. O2 - Dead plants, animals, and their excreta decomposed by micro-organisms. Usually absent in agricultural and deserts.
A-Horizon (Leached horizon) Topsoil - Often rich in humus and minerals.	It consists of topsoil with humus, living creatures, and in-organic minerals. A1 - Dark and rich in organic matter because of the mixture of organic and mineral matters. A2 - Light-colored layer with large-sized mineral particles.
B-Horizon (Accumulation horizon) (Subsoil - Poor in humus, rich in minerals)	It consists of iron, aluminum, and silica-rich clay organic compounds.
C - Horizon (Partially weathered horizon) Weathered rock Fragments - Little or no plant or animal life.	It consists of parent materials of soil, composed of a little amount of organic matter without life forms.
R Horizon (Parent material) Bedrock	It is a parent bedrock upon which underground water is found.