digging into the diversity:

soil orders


pedogenesis is the formation of soil. over time, as energy flows through the system (in the form of heat, precipitation, biological activity, etc); soils weather and evolve, forming distinct layers and other morphological features.

energy flowthrough timebiology, climate, topographyclay or mineralbuild-uporganic matter build-upleaching of mobile elementslittlechangeCAEBCparent material

soil profile

the distinct layers that develop are called horizons, and the way they are arranged is called a soil profile. like chapters in a book, soil horizons provide a history of the landscape and indicate how a soil might function in the present.

r - bedrockc - parent materialb - accumulation zonesubsoile - eluviated zonea - topsoilo - organic layer

pedogenic processes

lessivageilluviationcalcificationpodzolizationsalinizationgleizationdesilicationSiSipedoturbationmelanizationCCCeluviationbioturbationpedoturbationphysical mixing of the soil due to shrink-swell clays and freezing and thawing cycleszone of losssalinization accumulation of soluble salts in a horizoneluviationleaching or movement of materials (i.e clays, salts, organic matter) out of a horizon; zone of lossilluviationmovement of materials (i.e. clays, salts, organic matter) into a horizonSO4NO3zone ofaccumulationlessivagephysical transfer or leaching of clay into deeper horizonspodzolizationleaching or movement of iron, aluminum, and organic matter to a deeper horizon bioturbationthe biological mixing of soil by plant roots, earthworms, ants, termites, and more!gleizationiron reduced from 3+ to 2+ and concentrated in an anaerobic environmentmelanizationdarkening of surface horzion due to input and/or mixing of organic matterdesilicationremoval of silica from clays and other minerals (i.e. quartz), leaving behind iron and aluminum-based mineralsSO4NO3zone ofaccumulationzone oflossSO4NO3calcificationaccumulation and precipitation of carbonates in a horizon

soil orders

the diversity of soil forming factors and pedogenic processes gives rise to a diversity of soils, which are classified into 12 distinct groups called soil orders. the 12 soil orders are found all over the world with similar soils appearing under similar climates or ecosystems.


the baby soil


the adolescent soil


the dry soil


the volcanic soil


the prairie soil


the shrink-well soil


the frozen soil


the wetland soil


the forest soil


the boreal soil


the old soil


the tropical soil


the human soil

soil diversity

the diversity of soils beneath our feet gives rise to the diversity of plants, animals, and ecosystems on earth, which in turn, influence the development and diversity of soils. it's all connected!.