OBJECTIVE FORESTRY

Detailed explanation-1: -The A horizon is the top layer of the mineral soil horizons, often referred to as ‘topsoil’. This layer contains dark decomposed organic matter, which is called “humus".

Detailed explanation-2: -Most commonly called topsoil, the A horizon is a layer of mineral soil that has a defined soil structure, and it is mostly made up of humus (decayed organic matter). The A horizon may be a result of soil disturbance by plant and animal activity. It is one of the layers we test for texture in the soils contest.

Detailed explanation-3: -A1 horizon – Top layer of mineral soil with organic matter content and significant biological activity. Usually darker in colour than horizons below.

Detailed explanation-4: -Subsoil is typically equivalent to the O horizon. The dark brown and black humus found in many soils does not mix well with clay minerals so there is very little contact between these two soil components. A, B, C and E horizons are found in all soils.

Detailed explanation-5: -B horizons: are commonly referred to as the subsoil. They are a zone of accumulation where rain water percolating through the soil has leached material from above and it has precipitated within the B horizons or the material may have weathered in place.