Soil classification system of the Food and Agriculture Organization

soil group abbrevi-

ation defining

characteristics name

derivation percent

of Earth's

land area

Soils defined by parent material

Andosol AN volcanic ejects an do (Japanese: "dark soil") 0.88

Arenosol AR sands arena (Latin: "sand") 7.17

Histosol HS organic matter histos (Greek: "tissue") 2.51

Vertisol VR swelling clays vertere (Latin:

"to turn") 2.67

Soils defined by topography

Fluvisol FL alluvial lowlands fluvius (Latin: "river") 2.79

Gleysol GL waterlogged

lowlands gley (Russian: "mucky soil

mass") 5.74

Leptosol LP eroded uplands leptos (Greek: "thin") 13.19

Regosol RG climate-limited,

thin soil rhegos (Greek: "blanket") 2.07

Soils defined by climate, organisms, and time

Calcisol CL calcium carbonate accumulation calix (Latin: "lime") 6.38

Gypsisol GY gypsum

accumulation gypsum (Latin: "calcium sulfate") 0.72

Solonchak SC salt accumulation sol chak (Russian: "salty area") 2.55

Solonetz SN sodium

accumulation sol etz (Russian: "strongly salty") 1.08

Durisol DU silica accumulation durum (Latin: "hard") —

Chernozem CH cold steppe environment chern zemlja (Russian: "black earth") 1.83

Umbrisol UM cool, wet steppe environment umbra (Latin: "shade") 0.80

Kastanozem KS warm, dry steppe environment castanea zemlja (Latin-Russian: "chestnut earth") 3.71

Phaeozem PH warm, wet steppe environment phaios zemlja (Greek-Russian: "dusky earth") 1.51

Acrisol AC seasonally dry

humid tropics acer (Latin: "strong acid") 7.97

Alisol AL humid subtropical

and warm

temperate areas alumen (Latin: "aluminum") 0.80

Ferralsol FR extensively

weathered; humid tropics ferrum alumen (Latin: "iron-

aluminum") 5.98

Lixisol LX driest humid

tropics lixivia (Latin: "washing") 3.47

Nitisol NT extensive clay migration; tropics nitidus (Latin: "shiny") 1.59

Plinthosol PT fluctuating water

table; plinthite plinthos (Greek: "brick") 0.48

Luvisol LV clay accumulation; distinct seasons luere (Latin: "to wash") 5.18

Planosol PL clayey horizon planus (Latin: "flat") 1.04

. Podzol PZ accumulation of

iron and aluminum oxides and humus pod zola (Russian: "under ash") 3.87

Albeluvisol AB cold temperate

area; bleached

horizon over

clayey horizon albus (Latin: "white") 2.55

Cryosol CR alternate freezing

and thawing; waterlogged

during thaw; permafrost within

1 metre (3 feet) of

the land surface kryros (Greek: "cold") —

Anthrosol AT extensive human modification anthropos (Greek: "man") 0.004

Cambisol CM little soil

formation; recent cambiare (Latin: "to change") 11.96