Soil classification: orders

Gelisols (el)

- contains permafrost

- depend on climates

- do not have a diagnostic horizon

permafrost

can undergo soil processes

Gelisols found mostly in

-polar regions

-mostly on island and cont. edge

- high elevations

Entisols (ent)

- immature soil

- recent soils

- no genetic horizons, only a weak A

-little development

setting of entisols

places that have new parent material

inceptisols(ept)

- inception of B horizon

- weakly developed profile

- more developed than entisols

inceptisols setting

- widely distributed (found anywhere)

- steep slopes, mt. regions, young geomorphic surfaces

- resistant parent materials

what soil order supports over 20% of the global population

inceptisols

Andisols(ands)

-developed from volcanic material, particularly ash

- contain glass, many short-lived unstable colloids

- high water-holding capacity

-buried soil horizons are common

Histosols(ist)

organic soils

- 20-30% OM

- @ least 40cm thick

-low bulk density

-wetland soils

Histosols distribution

- in northern locations b/c cold inhibits the recycling/decomposition

Aridisols(ids)

- dry much of the year

- accumulation of CaCO3, gypsum, quartz, NaCl, evaporitic material

Mollisols(olls)

-grassland soils

- organic-rich

- thick surface horizon and deep

- thick A horizon not O horizon

Vertisols(erts)

- clay rich

-shrink-swell

-vertical cracking

Alfisols(alfs)

-moderately leeched

- relatively high native fertility

-forests

-accumulated clays in subsurface

Spodosols(ods)

- e horizon

-subsurface accumulation of humus

- complexed with Fe and Al

-coarse parent material

-forest

-naturally low fertility

-not much oxidation

Spodosols(ods) setting

wet and cold areas

Utisols(ults)

-Old soils which have been leached low fertility

-lot of development

- low LEC

-accumulation of clays

- red

Utisols setting

humid areas, temperate to tropical

oxisols

intensely weathered soils of tropical and subtropical environments, lateraliation

-very red

-low LEC

- high in Fe, Al

- chem weathering

- lack of OG parent material