Soils: 1_General Physical Properties of Soil and Soil Formation in Alberta Flashcards
(37 cards)
What are the five main soil-forming factors?
The five main influences on soil development are climate, organisms, topography, parent material, and time.
What is parent material?
The unconsolidated organic and mineral material in which soil forms.
What is residual material?
Parent material formed from bedrock weathered in place.
What are eolian deposits?
Sediments moved and deposited by wind, commonly sand and silt (loess).
What are alluvial deposits?
Sediments deposited in flowing water environments like rivers, commonly sand and gravel.
Glacio-fluvial refers to deposits associated with glacial meltwater.
What are colluvial deposits?
Sediments moved and deposited by unchannelized flow on slopes.
What are glacial deposits?
Sediments deposited directly by or in connection with glacial ice.
What is glacial till?
Sediments deposited directly by glacial ice, typically a poorly sorted mixture of particle sizes.
What are lacustrine deposits?
Sediments deposited in still, fresh-water lakes.
Glacio-lacustrine refers to deposits associated with glacial lakes, commonly well-sorted sands, silts, and clays.
What are organic deposits?
Parent materials formed from accumulated plant and animal residues.
What is pore space?
The spaces between and within soil aggregates, occupied by water and air.
What are macropores?
Large soil pores (usually > 0.08 mm) between aggregates that drain freely by gravity.
What are micropores?
Small soil pores (usually < 0.08 mm) within aggregates, retaining water against gravity.
What is pore connectivity?
The degree to which soil pores are connected, influencing the movement of water, air, and roots.
What is soil structure?
The arrangement of primary soil particles (sand, silt, clay) into aggregates.
What are aggregates (peds)?
Combinations or arrangements of primary soil particles into stable units.
What is granular structure?
Loosely packed, crumbly soil aggregates typically found in surface soils with high organic matter.
What is platy structure?
Horizontally layered soil structure, often indicative of compaction or formed in bleached eluvial horizons.
What is soil organic matter (SOM)?
Composed of plant and animal residues at various stages of decomposition, microbial biomass, and products of microbial synthesis.
What is humus?
Stable, well-decomposed organic matter.
What is litter?
Fresh or partially decomposed plant and animal residues on the soil surface.
What is cation exchange capacity (CEC)?
The ability of a soil to retain positively charged ions (cations), important for nutrient retention.
What is buffering capacity?
The ability of a soil to resist changes in pH.
What is weathering?
The breakdown of rocks and minerals by physical, chemical, and biological processes.
