soil formation

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June 24, 2026

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Soil formation, or pedogenesis, is the complex process by which soil develops over time. It is influenced by five key factors: parent material, topography, climate, organisms, and time.12345

Parent Material: The original geological material from which soil forms, influencing its mineralogical composition and texture.2
Topography: Includes elevation, aspect, and slope, affecting water runoff, erosion, and accumulation of materials.1
Climate: Temperature and precipitation drive chemical reactions, organism activity, and the transport of particles within the soil.3
Organisms: Vegetation, animals, and humans contribute organic matter and alter soil structure and chemistry.5
Time: The duration over which these factors interact, allowing for the development of distinct soil horizons.4

Soil horizons are distinct layers parallel to the land surface, formed by these processes. Common designations include O (organic litter), A (humus accumulation), E (leached layer), B (subsurface accumulation), C (unweathered material), and R (bedrock).6

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soil
Soil formation
As stated at the beginning of this article, soils evolve under the action of biological, climatic, geologic, and topographic influences. The evolution of soils and their properties is called soil formation, and pedologists have identified five fundamental soil formation processes that influence soil…
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As stated at the beginning of this article, soils evolve under the action of biological, climatic, geologic, and topographic influences. The evolution of soils and their properties is called soil formation, and pedologists have identified five fundamental soil formation processes that influence soil…
Read More

valley
Hillslopes
…in the upper parts of soil-mantled slopes, as near the drainage divide. The noted American geomorphologist G.K. Gilbert elucidated the principles applying to convex slopes in his study of piles of mining-waste debris in California. The processes of soil creep and raindrop splash erode soil on the upper parts of…
Read More
…in the upper parts of soil-mantled slopes, as near the drainage divide. The noted American geomorphologist G.K. Gilbert elucidated the principles applying to convex slopes in his study of piles of mining-waste debris in California. The processes of soil creep and raindrop splash erode soil on the upper parts of…
Read More

bryophyte
Ecology and habitats
…ultimately to the initiation of soil formation. This in turn produces a substratum attractive to seed plant colonists that invade these mossy sites and, through their shading, eliminate the pioneer mosses but create a shaded habitat suitable for other bryophytes. These new colonists, in turn, are important in nutrient cycling…
Read More
…ultimately to the initiation of soil formation. This in turn produces a substratum attractive to seed plant colonists that invade these mossy sites and, through their shading, eliminate the pioneer mosses but create a shaded habitat suitable for other bryophytes. These new colonists, in turn, are important in nutrient cycling…
Read More