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Term
Oxidized Fe3+ (ferric iron) |
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Definition
reds, yellows; well-drained |
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Reduce Fe2+ (ferrous iron) |
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Definition
greys, blues; poorly drained |
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Term
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Definition
30" or greater depth to grey or mottles |
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Definition
18-30" depth to grey or mottles |
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10-18" (mostly brown) depth to grey or mottles |
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Definition
10-18" (mostly grey) depth to grey or mottles |
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Term
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Definition
- 2-0.5 mm (usually quartz)
- gritty feeling
- large voids, rapid draining
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Term
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Definition
- 0.05-0.002 mm (quartz or feldspar)
- floury feel to soil
- smaller pores (more numerous), retains water
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Term
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Definition
- < 0.002 mm
- large specific surface area
- colloidal (stays suspended in water)
- pores very small, water movement very slow
- shaped like flakes or platelets
- properties depend on type/amount
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Term
Clay has a _____________ ribbon. |
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Definition
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Term
Clay loam has a ______ ribbon. |
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Definition
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Loam has a _______ ribbon. |
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Definition
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Silt has a ______ texture. |
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Definition
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Term
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Definition
arrangement of primary soil particles |
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Term
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Definition
characteristics of surface (A) horizons; subject to wide and rapid changes |
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Definition
Common in E-horizons, may occur in any part of the profile; often inherited from parent material of soil or caused by compaction |
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Definition
Common in R horizons, particularly in humid regions; may occur in A horizons |
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Definition
Usually found in B horizons; most common in soils of arid and semi-arid regions |
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Term
Sand ________, _________ to transport |
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Definition
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Term
Clay is _______ to detach, _______ to transport |
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Definition
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Term
Silt is ________ to detach, _______ to transport |
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Definition
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Term
Biological Processes That Form Soil Aggregates |
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Definition
- soil organisms (earthworms)
- particle enmeshing by sticky network of roots (polysaccharides) and hyphae (Glomalin)
- production of organic glues (not water soluble) by microorganisms
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Term
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Definition
- major agent in spheroidal formation and stabilization
- carbon source for a, b, c & above
- tillage
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Definition
- incorporates OM (short term)
- increases OM oxidation (long term)
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Term
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Definition
- interped spaces
- fast drainage
- rapid gas exchange
- biopore (created by living organisms)
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Term
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Definition
- intraped spaces
- usually filled with water
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Term
As pore space increases, _______ decreases |
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Definition
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Term
Finer silt loams, clay, clay loams = |
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Definition
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Term
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Definition
As depth decreases, so does Db |
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Definition
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Term
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Definition
- due to aggregate dispersion (high salt content, rainfall action)
- clogged pores by individual spore particles
- poor seedling emergence
- high runoff rates
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Term
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Definition
- promotes flocculation
- prevents soil crusting
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Term
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Definition
similar to natural organics |
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Term
Soil Tilth Management Guidelines |
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Definition
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minimize tillage
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time traffic activities (soil should be dry as possible)
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mulch soil surface
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add OM
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include sod crops
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use cover crops or green manures
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apply gypsum with or without organic polymers
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Term
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Definition
- rate of gas exchange within atmosphere
- proportion of pore spaces filled with air
- composition of the soil air
- resulting oxidation/reduction potential
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Term
O2 availability controlled by: |
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Definition
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macroporosity
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water content
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O2 consumption
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Term
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Definition
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Atmosphere - 21% O2, 0.035% CO2, >78% N
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Soil Atmosphere - Same N, Lower O2, Higher CO2
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Definition
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Term
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Definition
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C6H12O6 + 6O2 → 6CO2 + 6H2O |
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Definition
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Term
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Definition
Fe3+, Mn4+, NO3-, and SO42- predominate |
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Term
Poorly Drained/Poorly Aerated Soil |
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Definition
Fe2+, Mn2+, NH4+, and S2- predominate |
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Term
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Definition
soils that are water-saturated near the surface fore prolonged periods when the soil temperature is high enough to result in anaerobic conditions |
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Definition
- wetland hydrology or water regime
- hydric soils
- hydrophytic plants
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