Unit 4: Soils

Question 1

what is soil

Answer 1

• interface between the lithosphere and biosphere that supports all animal and plant life
• it results from physical chemical biological and human processes on parent material

Question 2

what are O, A, B, C and R

Answer 2

• O Horizon: top most layer, organic matter at different stages of composition that retains waster and nutrients
• A horizon: humus and other organic materials are mixed with mineral particles. is the zone of translocation from which eluviation has removed finer particles and soluble substances and can be divided into Ah (darker and organic) and Ae (loss of material)
• B Horizon: a mineral soil layer which is strongly influenced by illuviation. often coloured by oxides of iron and aluminum
• C horizon: weathered parent material,, particles could be from clay to boulders
• R horizon: a layer of unweathered rock

Question 3

four main processes that create soil horizons:

Answer 3

• addition: precipitation and organic matter and nutrients
• transformations: organic matter to humus. one year to two year minerals
• translocations: eluviation and illuviation. Humus, clay and ions
• losses: leaching and erosion

Question 4

five controls on soil type

Answer 4

• parent material: residual material, transported material and accumulated organic material
• climate: long term climate patterns act upon the available parent material at surface to develop canada’s soil types and regions over long periods of time
• biology: regional scale, matching patterns of forest and soils
• relief: topography = slope. affects soil drainage and soil erosion. Hillside has a steep slope and thin soil well drained and eroded. the bottom is thick soil. poorly drained and may be waterlogged
• time: age of the soil depends on where are you are in canada

Question 5

properties of parent materials for soils in canada that are glacial and non glacial

Answer 5

• glacial: glacial till and moraine, glacio-fluvial and glacial - marine sediments (result of marine inundation prior to isostatic rebound (glacio-lacustrine)
• non glacial: exposed bedrock, colluvium - hillslope sediments and alluvium

Question 6

what is the parent material of the canadian shield and the artic region

Answer 6

• canadian shield: climate generally poor since topography gives poor drainage. the parent material is typically glacio marine deposits since this reigon has undergone some isostatic rebound or glacio lacustrine deposits which is quite extensive throughout ontario Manitoba and Saskatchewan
• artic region: sedimentary rock, easy erosion but poor climate. the parent soil is likely glacial till

Question 7

how does soil porosity affect the moisture holding capacity of soils

Answer 7

• pores in soil horizons control the intake slow and drainage of water. soil type determines the amount of water soil can hold and the amount of water available to plants. an example would be the prairies in the summer

Question 8

what type of soil is usually found under forested ecosystems in canada

Answer 8

• brunsolic soils are found under forested ecosystem.
• normally immature soil the most identifying trait is the presence of a B horizon that is brownish in colour

Question 9

what soil type is usually found under grassland ecosystems in canada

Answer 9

• cherozemic soils
• common to grassland ecosystems
• this soils is dark in colour and has an A horison that is rich in organic matter
• common in the canadian prairies

Question 10

what are organic soils and where in canada are they found

Answer 10

• composed mainly of organic matter in various stages of decomposition
• are common ins swamps, fen and bogs
• the profiles of these soils have an obvious absence of mineral soil particles
• most common in ontario and other climate similar environments (broeal forest) in peatlands