Hardscape 1 - Terms and Definitions

E Horizon (Eluvial Layer)

Soil layer which acts as a primary leaching zone, removing minerals from the upper soil layers through water percolation.

Soil Tilth

It describes the physical condition of soil in relation to its ease of tillage, fitness as a seedbed, and suitability for plant growth.

B Horizon (Subsoil)

This soil layer serves as the zone of illuviation; it receives and accumulates materials eluviated from upper soil layers.

C Horizon (Parent Material)

Soil layer composed of weathered rock fragments or sediments which provides the mineral basis for the development of upper soil layers.

B Horizon (Subsoil)

Supplemental layer to topsoil that provides added rooting volume for soil stability, extra nutrients, and water storage.

E Horizon (Eluvial Layer)

Light-colored, mineral soil layer characterized by intense leaching of clay, iron, aluminum, and organic matter.

Soil

This is a vital component for the existence of many forms of life that have evolved on our planet.

Soil Horizons

Interdependent horizontal layers of soil with different characteristics (morphological, physical, chemical, mineralogical) that forms the soil profile.

A Horizon (Topsoil)

Usually dark in color, light in texture, and porous, soil in this layer serves as the major rooting medium for most of the plant roots.

O Horizon (Organic)

This soil horizon functions as:mulch that reduces evaporative water losseslowers daytime and maintains nighttime surface soil temperaturescontributes organic matter for soil tilthacts as a source of energy for soil organisms

A Horizon (Topsoil)

This layer is primarily composed of mineral particles mixed with humus and other organic materials.

R Horizon (Bedrock)

The soil layer of unweathered bedrocks which represents the limit of excavation, often requiring heavy machinery for removal.

O Horizon (Organic)

Topmost layer of most soils. It is composed mainly of plant litter at various levels of decomposition and humus.

Soil

Primary growing medium for plants.

A Horizon (Topsoil)

Zone of translocation from which eluviation has removed finer particles and soluble substances.

Soil Profile

A vertical cross-section of soil, revealing distinct horizontal layers called horizons.