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diagnostic horizon
- Bt
- illuvial horizon enriched in phyllosilicate clay
- usually have eluviated (Ae) horizon above
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necessary thickness of Bt horizon
>/= 5cm
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clay skins over ____ of area
1%
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characteristic structure?
- moderate prismatic macrostructure
- blocky mesostructure
-
-
pH?
- sola relatively high base status
- pH neutral
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soil moisture regime
humid to perhumid
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distribution in canada
- western canada: northern interior plains (boreal forest and forest grassland transition)
- eastern canada: st. lawrence lowlands and niagara region
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-
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gray brown luvisols GG
- eastern canada
- mild humid climate
- earthworm activity
- thin LFH, mull Ah
- mean annual soil temp > 8°C
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gray luvisols GG
- western canada
- cool/cold climate
- boreal forest - dominated by aspen
- mainly LFH then Ae
- PGM - glacial till
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gray luvisol GG subgroups (9)
- orthic gray
- brunisolic gray luvisol
- podzolic gray luvisol
- gleyed gray luvisol
- dark gray luvisol
- solonetzic gray luvisol
- vertic gray luvisol
- fragic gray luvisol
- gleyed versions of gray luvisol SGs
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brunisolic gray luvisol
- bisequa: a soil within a soil
- Bm forms in the Ae horizon
- Bm must be 5+cm, chroma > 3
- not very common
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podzolic gray luvisol
- also a bisequa
- mini podzol in the Ae, Bf horizon
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fragic gray luvisol
- fragipan in lower solum
- high bulk density, appears cemented, hard when dry
- slakes in water
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major soil forming factors: climate
- humid to perhumid
- more leaching water moves through solum
- solum usually ~1m
- Ck horizon common
-
major soil forming factors: organism
- trees, less base cycling than grasses
- fungi: major decomposing organisms, release organic acids facilitates lessivage
-
main soil forming factor: relief
- develop on landscape where zonal features are expressed
- well drained topographic conditions
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major soil forming factors: PGM
- glacial till: calcareous and fine
- buffered so that chemical weathering is held in check
-
major soil forming factors: time
> 5000yrs
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management of luvisolic soils
- agricultural limitation: thin A which is slightly acidic, low organic C content
- research into overcoming nutrient deficiencies, improving crop and soil quality
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lessivage
physical transfer of clay by flowing water
-
______ in A horizon facilitates translocation of clay
sodium
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