Soil Orders

Andisols

-Have volcanic parent material -Very dark

Ultisols

-High clay content, acidic -Found in subtropics and tropics -Very weathered

Mollisols

-High in organic matter content due to plant roots -Very fertile, often converted into farmland -Found mainly in grasslands

Gelisols

-High in organics due to cold temps slowing down decomposition. -Permafrost

Spodosols

-Highly leached -Found in coniferous/boreal forests -High acidity content

Oxisols

-Highly weathered soil -Low in nutrients, high in Al and Fe oxides -Found in tropical climates

Alfisols

-Moderately leached -Found in temperate deciduous forests

Inceptisols

-More weathered form of entisols -Layers/horizon begins to form

Aridisols

-Mostly made of clay/non-weathered material (due to lack of water) -Also high in salt content due to lack of water -Characteristic of hot, dry climates (PET is higher than actual precipitation)

Entisols

-The least weathered, newest form of soil -Very uniform, no horizons

Vertisols

-Very clay rich -Expands and contracts w/changes in moisture -Leads to inversions of soil layers (so older material can be found higher up)

Histosols

-Very dark, high in organic material -Low oxygen environment prevents decomposition -Mainly found in peatlands and wetlands