-
diagnostic horizon(s)
Bg, Btg, Bgf, Btgf, Bng
-
-
chroma of ____ or hues _____
-
prominant mottles _____ of area
> 2%
-
if hue is redder than 5YR, chroma = ______
</= 2
-
if hue is yellower than 10YR, chroma= ___
</= 3
-
contrast
- the difference bw the feature colour and the matrix colour (bulk soil colour)
- assessed using munsell colour charts
-
major soil forming factors of genesis: climate
- subaquic to peraquic (saturated for >10mo/yr) moisture regimes
- subarctic to mesic temperatures
- in all precipitation zones - semi-arid to humid
-
major soil forming factors of genesis: organism
- hydrophytic species of trees, shrubs, sedges, mosses
- forest or meadows, grasses in dry zones
-
major soil forming factors of genesis: relief
a major factor, ex. poorer to very poor drainage
-
major soil forming factors of genesis: parent material
- wide range: glacial till, lacustrine, alluvial deposits
- could be calcareous or saline
-
major soil forming factors of genesis: time
long enough to reach steady state
-
gleying
- development of drab grey colours
- reduction of goethite to ferrous oxidation state to form ferrihydrite
-
mottling
- accumulation of iron oxide in splotches within the soil matrix
- Fe in its 3+ oxidation state (ferric iron)
-
faint mottling
little accumulation of iron oxide
-
prominent mottling
massive accumulations as in fera horizons (Bf, Bgf)
-
redox reactions in soils
- occur in soils because of the ongoing production of electrons through organic matter decomposition
- organic matter is the primary electron donor in soils
-
-
humic gleysols
- Ah > 10cm
- No Bt
- usually assoc. with chernozems
-
Gleysol gleysols
- shallow Ah if present
- no Bt
- hydrophytic forest marsh vegetation
- shallow water table
- assoc. with brunisols and regosols
-
luvic gleysols
- have a Btg (translocation of clay)
- usually have an Aeg or Ahe
- may have an Ah
- often in slow recharge areas
- usually transitional to luvisols
-
subgroups of the gleysols (7)
- orthic
- rego
- fera
- humic luvic SG
- fragic luvic SG
- solonetzic
- vertic
-
distribution in canada
- occurs throughout canada
- subaquic (< 120 days saturation) to peraquic (>300 days
- all temp classes except permafrost
- poorly drained positions
-
zone I in hydrological profile
- surface zone
- aerobic
- may be moist from capillary fringe
- roots
- high chroma
-
zone II in hydrological profile
- aerobic and anaerobic cycling
- middle zone
- water table excursions
- alternating redox conditions
- maybe perched water table
- zone of mottling and gley
-
zone III of hydrological profile
- anaerobic
- below water table
- often groundwater discharge zone
- mainly gleyed soil, little mottling
|
|
