Layers in fully developed soils that exhibit distinctive characteristics are known as?

Soils that have been fully developed typically exhibit distinct layers, known as horizons. Each horizon in the soil profile has its own unique composition, structure, color, and texture, which reflect the processes of soil formation, including weathering and organic matter accumulation. These layers can provide valuable insights into the soil's history, nutrient availability, and overall health.

The term "horizons" is specifically used in soil science to categorize these layers, making it a standard term within the field. The uppermost layer, known as the O horizon, is rich in organic material, while deeper layers (A, E, B, C, and R) represent varying degrees of soil evolution and alteration. This nomenclature helps professionals and researchers communicate effectively about soil characteristics and management practices.

The other terms mentioned, such as strata, profiles, and levels, do not specifically convey the same meaning within the context of soil science. Strata usually refer to geological layers in rock formations, profiles indicate the vertical sequence of soil horizons but do not denote the individual layers themselves, and levels is a more general term that doesn’t capture the distinctive nature of the soil layers. Therefore, horizons are the appropriate term to describe the defined layers found in fully developed soils.