The solum in soil science consists of the surface and subsoil layers that have undergone the same soil forming conditions. The base of the solum is the relatively unweathered parent material. Solum and soils are not synonymous. Some soils include layers that are not affected by soil formation.

What does solum mean?

noun, plural so·la [soh-luh], so·lums. the upper part of the soil profile, which is influenced by plant roots; the A horizon and the B horizon.

What is a solum in geography?

(pl. sola) The upper part of a soil profile, above the parent material, in which processes of soil formation occur, and within which most plant roots and soil animals are found. From: solum in A Dictionary of Earth Sciences »