Midterm Flashcards
Which horizon ID has illuviation?
Bt
What does the horizon suffix ‘m’ mean?
change in colour or texture or both
What soil structure does Bm have?
blocky or prismatic
What does the horizon Bmk tell us?
partial removal of carbonates
Decalcification?
acid reaction that removes carbonates from a horizon
Calcification?
Secondary carbonates. deposition of carbonates transported down from upper horizon (Cca)
Salinization?
accumulation of soluble salts
Glacial till PM
LETHBRIDGE AREA. transported by glaciers, tilling the land. hummocky, LOAMY medium textured. coarse fragments. loam, sandy loam, clay loam, sandy clay loam
Glacio fluvial
CHIN AREA. transported by flowing water glacial melt. high sand content. slight sloping
What is a shelter belt?
use of trees to break wind. caragana plant
Glacio lacustrine
COALDALE. lake water stagnant. undulating and flat level. clay textured. rarely coarse fragments.
Lethbridge typical soil profile?
Ah, Bm, Ck
What does the suffix n tell us?
high in sodium. columnar
The darker the soil zone on the prairies is a factor of?
amount of precipitation, highest precip in black, lowest in brown
What 2 nutrients are immobile?
phosphorus and potassium
Which 2 nutrients are mobile?
nitrate and sulfate
Best cation to form aggregates?
Ca
Cation most likely to cause clay dispersion?
Na
Why is a dispersing agent (calgon aka sodium hexametaphosphate) added to soil prior to determining soil texture?
completely separates the particles
Which particles settle after 40 seconds?
sand
Which particles settle after 2 hours?
silt
Which particles never settle?
clay
Why is it necessary to correct hydrometer reading?
- addition of dispersing agent
- change in temp
What horizon sequence is typical of luvisolic areas?
Ae, Bt, Ck
Regional influence on soil?
Climate
Local influence on soil?
topography
What is flocculation?
the same as aggregation
What is bulk density?
weight of soil divided by volume
what is particle density?
mass per unit of volume
What is soil porosity?
the nonsolid volume of soil
Relationship between bulk density and porosity?
Inversely related. as bulk density increases, porosity decreases.
What is the influence of compaction on bulk density?
increases the bulk density and decreases porosity
How does organic matter influence bulk density?
high OM decreases the bulk density and increases pore space.
Which texture of soil makes a ribbon stronger than 5 cm?
clayey textured soils
Which textured soil makes a ribbon less than 2.5 cm?
sandy
