Each soil forms as a unique expression of five soil-forming factors (climate, vegetation, topography, parent material, and time) that work through soil processes. These soil processes can be considered in the following four groups: additions, losses, transformations, and translocations.
Additions
Addition of material to the developing soil profile from outside sources, such as organic matter from leaves, dust from the atmosphere, or soluble salts from groundwater.
Organic Examples
Deciduous forest floor
Evergreen forest floor
Bog
Mineral Example
Landslides
Translocations
Translocation (transportation) of inorganic and organic materials from one horizon to another, either up or down (material is primarily moved by water but may also be moved by soil organisms).
Pedoturbation
Faunal ants
Faunal earthworms
Floral
Clay Accumulation
Argilipedoturbation
Cryoturbation
Elluviation and Illuviation
Transformations
Transformation of soil constituents from one form to another, such as through mineral weathering and organic matter breakdown.
Examples
Gleysol
Brunisol
Losses
Loss of material from the soil profile by leaching to groundwater, erosion of surface material, or other forms of removal (often transformation and translocation result in the accumulation of material in a particular horizon).
Erosion
Organic soil
These processes of soil genesis, operating under the influence of environmental factors, give us a logical framework for understanding the relationships between particular soils and the landscapes and ecosystems in which they function.
This approach is known as internal process modeling. In analyzing these relationships for a given site, ask yourself the following four questions:
- What are the materials being added to this soil?
- What transformations and translocations are taking place in this profile?
- What materials are being removed?
- How have climate, organisms, topography, and parent material at this site affected these processes over time?