Knowra Soil formation Soil formation Soil formation is the development of soil from parent material through physical, chemical, and biological processes. Its rate and outcome depend on climate, organisms, topography, parent material, and time.
Weathering : The breakdown and alteration of rocks and minerals at or near Earth's surface. Physical fragmentation and chemical alteration release minerals that become part of developing soil.
Parent material : The mineral or organic material from which a soil develops. Its composition and texture set starting conditions for weathering and soil development.
Soil classification : The organization of soils into groups based on measurable properties and inferred development. Formation processes help account for the diagnostic horizons and properties used to classify soils.
Laterite : A soil or rock enriched in iron and aluminum oxides through intense weathering and leaching, common in tropical regions. Warm, wet conditions drive the strong chemical alteration that produces lateritic profiles.
Soil horizon : A distinct layer in a soil profile, shaped by processes such as organic accumulation, leaching, and mineral alteration. Formation differentiates the surface and subsurface into layers with different properties.
Climate : The long-term pattern of temperature, precipitation, and other atmospheric conditions in a region. Temperature and water availability govern weathering, leaching, and biological activity.
Soil erosion : The removal and transport of soil by water, wind, ice, or gravity. Erosion can remove developed horizons faster than formation replaces them.
Podzol : A strongly leached soil with an ash-gray upper horizon and a subsurface accumulation of organic matter and metals. Acidic litter and downward movement of dissolved compounds shape its distinctive horizons.
Leaching : The movement of dissolved substances downward through soil with percolating water. It removes some materials from upper layers and deposits them deeper in the profile.
Soil biota : The community of organisms living in soil, including microbes, plants, animals, and fungi. Living organisms decompose residues, cycle nutrients, and physically alter soil.
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