Ultisols

 

Strongly leached, acid forest soils.

Have relatively low native fertility.

Found primarily in humid temperate and tropical areas of the world typically on older, stable landscapes.

Intense weathering of primary minerals has occurred.

Soils deficit in Ca, Mg and K.

A subsurface layer of clays is often yellow or red indicating the presence of iron oxides.

 

Utilsols occupy about 8% of the global ice-free land.

They support 18% of the world's population.

They are the dominant soil of the southeastern US.

 

With inputs of lime and fertilizer these soils can support agriculture.

 

 

 

 

 

 

 

 

Western Arkansas Ultisol

 

Formed in metamorphosed sandstone.

Has typical horizon development.

 

 

 

Coastal Plain of North Carolina

 

Well-drained Ultisol in the foreground, poorly drained Ultisol in the background.

 

 

 

Coastal Plain of North Carolina Ultisol Profile

 

Formed in loamy marine sediments.

Notice the light-colored top E horizon.

Once forested, these well-drained soils have been mostly cleared of trees for agriculture.

 

 

 

Plinthite Blocks

 

An ironstone hardpan formed from repeated wet-dry cycles.

Is used as a building material.