Soil pH and Classification
Terms
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- Umbric
- epipedon dark colored, >1% organic matter, >25cm thick,(similar to mollic except less than 50% base saturation)
- Mollic
- Epipedon dark colored, >1% organic matter, >25cm thick, >50% base saturation, soft
- Ochric
- Epipedon light color, low organic matter, thin, hard when dry
- Melanic
- Epipedon black, thick, developed on volcanic ash
- Histic
- Epipedon peaty, >16% organic matter, under permafrost or in wetlands
- Argillic
- Subsurface (Bt) accumulation of illuviated clay
- Cambic
- Subsurface (Bw) some color development, but no accumulations, not much going on
- Spodic
- Subsurface (Bh) accumulation of organic matter
- Oxidic
- Subsurface (Bs) accumulation of Fe and Al oxides
- Alfisols
- ALF Ochric & Argillic (Bt)— mostly Midwest near Mississippi- develops under cold, wet deciduous forest, generally productive agricultural soils—MED weathering
- Andisols
- AND ash— Pacific NW- formed on volcanic ash—LOW weathering (but more than entisols)
- Aridisols
- ID Ochric & not much—SW (east of Sierra Nevada), aridic/desert—LOW/MED weathering
- Entisols
- ENT Ochric & weakly developed Cambic (Bw)— recent alluvium on flood paths, sand dunes, thin soils over recently developed bedrock/parent material—LOWest weathering
- Gelisols
- EL Permafrost— most of Alaska/arctic and high elevations—LOW weathering
- Histisols
- IST Histic & __ — wetland areas near great lakes, shorelines, and Florida—LOW weathering
- Inceptisols
- EPT Ochric & Cambic (Bw)— Appalachian mts, mts, recently exposed parent material, W-coast —LOW
- Mollisols
- OLL Mollic & ~Argillic— dominant in the Midwest, agricultural, formed under grassland—MED
- Oxisols
- OXI Ochric & Oxidic— HI and Puerto Rico, warm, humid tropical climates, low fertility--HIGHest
- Spodosols
- OD Ochric & Spodic— NE, parts of FL and near great lakes. Sandy soils under coniferous vegetation, cool climates, well drained—MED/HIGH
- Ultisol
- ULT & Argillic— SE moist, warm tropics, low fertility—MED/HIGH
- Vertisols
- ERT • Vertisols- Clay— Texas, Alabama, high content of shrinking & swelling clays (>30% clay)—LOW/MED
- What are the units of the soil taxonomy similar to kingdoms...?
- ⬢ OrderSuborderGreat Group-> Subgroup-> Family-> Series-> (Phase)
- Increases in acidity due to HUMAN-induced activities:
- ⬢Chemical fertilizers: creates nitric acid (HNO3) or sulfuric acid (H2SO4) and H+ disassociates. ⬢Acid rain from sulfuric acid and nitric acid in air pollution
- Increases in acidity due to NATURAL causes:
- •Release of CO2 by organic matter decomposition and root respiration leading to the production of disassociated carbonic acid (HCO3) •Al3+ is an acid forming cation and combines with hydroxyl to leave H+ in the soil solution. •Pine needles ↑ acidity, grassland has ↓ acidity, due to differences in precipitation