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". The technical definition of an A horizon may vary between the systems, but it is most commonly described in terms relative to deeper layers.

Detailed explanation-2: -The A horizon is the first of the three main layers of soil. Also known as topsoil, this layer is darkest in color (a dark brown or black) and best for plant growth. One of the reasons it is best for plant growth is that it is mineral matter mixed with humus.

Detailed explanation-3: -The A-Horizon or Topsoil This layer is rich in organic material and is known as the humus layer.

Detailed explanation-4: -B horizon. Also called the subsoil-this layer is beneath the E Horizon and above the C Horizon. It contains clay and mineral deposits (like iron, aluminum oxides, and calcium carbonate) that it receives from layers above it when mineralized water drips from the soil above.

Detailed explanation-5: -The A horizon or topsoil is thus also called the humus layer.