Term
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Definition
argillic with moderate or high base status
at least 35% CEC occupied by bases
not much organic matter
subsurface accumulation of illuvial clay often brownish colors
moderate weathering and leaching
moderate to high fertility |
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Term
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Definition
volcanic ash and high phosphorus retention
dark surface horizons
low bulk density
young and not highly weathered |
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Term
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Definition
aridic moisture regime and argillic, natric, calcic, petrocalcic, salic, or cambic
arid (dry) regions → frequently accumulation of salts
ochric epipedon |
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Term
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Definition
ochric epipedon with little or no soil development
young soils that are actively eroding on slopes or floodplains and recieve deposits of alluvium
sandy parent material
found under almost any vegetation in all climates
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Term
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Definition
permafrost
cold climates where upper profile thaws during warm periods
frost mixing (cyroturbation) is important process in these soils |
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Term
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Definition
greater than 20% organic matter and greater than 16 in thick
black much or peat |
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Term
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Definition
cambic (horizon of physical and chemical alternation) within 40 in of surface
bright colors
no subsurface horizons of diagnostic of other orders
occur in cool to very warm, semiarid to humid regions
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Term
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Definition
mollic
thick very dark colored, base-rich surface horizon
>50% base saturation
high base status thoughout profile
high fertility
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Term
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Definition
oxic
reddish colors
highly weathered of low fertility
subtropical and tropical regions
consist of iron and aluminum oxyhydroxides, kaolinite, quartz, and organic matter |
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Term
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Definition
spodic
black or very dark brown illuvial accumulation of humus and aluminum (w or w/o iron)
often overlying light colored E horizon
occur in humid regions
developed on coarse-textured parent materials |
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Term
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Definition
argillic or kandic with low base status
accumulation of iluvial clays: often reddish or yellowish colors
base saturation less than 35% in lower part of profile
highly weathered and leached: humid regions
low in natural fertility |
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Term
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Definition
high clay content with montmorillonite clay and deep, wide cracks at some time each year
shrink and swell |
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