The soil horizon below the O horizon and above the B horizon . In this layer, humus and other organic materials are mixed with mineral particles, while finer particles and soluble substances are washed out.

Mineral horizon formed at or near the surface in the zone of leaching and eluviation of materials in solution or suspension or of maximum in situ accumulation of organic matter. Distinguishing characteristics usually designated by a subscript e.g. Ah - humic( organic matter rich) horizon

The surface soil. See Soil Horizon.

The mineral horizon at or near the surface in which an accumulation of organic matter is mixed with mineral material.

the top layer of a soil profile; usually contains humus

The top layer of soil. Plant and other organic debris builds up in this layer. This is the part of the soil generally referred to as 'top soil'.