Soil Orders Flashcards
What is the diagnostic horizon?
a layer whose properties meet criteria specified
for purposes of classification
What is the O layer?
The layer organic horizon above mineral layer
What is the A layer?
The layer darkened by OM, coarse texture
What is the E layer?
The zone of maximum leaching, eluviation of clay, oxides
What is the B layer?
The zone of illuviation, accumulation of silicate clay, oxides (humid) or CaCO3 (arid)
What is the C layer?
The layer consisted of unconsolidated material, the zone of least weathering, least affected by soil-forming processes
What is the R layer?
Unweathered rock
What are subordinate horizons?
Describe specific nature of a soil horizon
(Cards 9-16) The following are subordinate horizons and their definitions.
Oa
Organic, highly decomposed
EB
Layer transition to B, more like E than B
Note: If vice-versa its the opposite- Example:
BE - Transitions to B, more like B than E
Oi
Organic; slightly decomposed
Oe
Organic; moderately decomposed
X is just a placeholder for a layer
Xk - What is k?
Accumulation of carbonates
Bh
Illuvial accumulation of organic matter
Bs
Illuvial organic matter and Fe and Al oxides in the B horizon
Bt
Accumulation of silicate clays
What is gleying?
What is a pedon?
A 3D unit. hint: Think like a Minecraft block
True or False:
Any true soil has all A, B, C and E horizons.
False
What is a polypedon?
Several contiguous pedons with similar characteristics.
Alfisols
Argilic, natric, or kandic horizon; high-to medium base saturation
Andisols
From volcanic ejecta, dominated by allophane or Al-humic complexes
Aridisols
Dry soil, ochric epipedon, sometimes argilic or natric horizon
Entisols
Little profil development, ochric epipedon common
