A Horizon: This horizon is also called the top soil. It contains remains of plants and animals which are undergoing decomposition to form humus. It is also known as the alluvial horizon or zone of eluviation which is impoverished by the washing of clay and fine soil particles down to the soil profit. It is the horizon with maximum biological activities of plants and soil micro-organisms.
B — Horizon: This horizon is also called the sub soil. It is the zone of enrichment (alluvial horizon or zone of illuviation). It is the accumulation of soil minerals, in which humus and other organic matter washed down from the A -horizon are converted into inorganic compound. '.
