SOCR 240 Soil Orders

Soil orders, formative elements, characteristics

Alfisols

alf

Andisols

and

Aridisols

id

Entisols

ent

Gelisols

el

Histosols

ist

Inceptisols

eat

Mollisols

oll

Oxisols

ox

Spodosols

od

Ultisols

ult

Vertisols

ert

Alfisols

argillic, natric, or Candice horizon; high-to-medium base saturation

Andisols

from volcanic ejects, dominated by allophone or Al-humic complexes

Aridisols

dry soil, ochre epipedon, sometimes argillic or natric horizon

Entisols

little profile development, ochric epipedon common

gelisols

permafrost, often with cryoturbation (frost churning)

Histosols

Peat or bog; >20% organic matter

Inceptisols

embryonic soils with few diagnostic features, ochric or umbric epipedon, cambic horizon

Mollisols

mollic epipedon, high base saturation, dark soils, some with argillic or natric horizons

oxisols

oxic horizon, no argillic horizon, highly weathered

spodosols

spodic horizon commonly with iron, aluminum oxides and humus accumulations

ultisols

argillic or kandic horizon, low base saturation

vertisols

high in swelling clays; deep cracks when soil is dry