MIDTERM 1 Flashcards
(164 cards)
1
Q
What is soil?
A
unconsolidated geologic or organic material of at least 10cm in depth – 3D body –
Affected by soil forming factors/processes and are capable of supporting plant growth
2
Q
What are the 3 phases of soil?
A
water (liquid), air and solids (organic and mineral)
3
Q
What is soil composed of (%)?
A
About half pore space (20-30% air and 20-30% H20) and half soil solids (45% mineral/geological and 5% organic)
4
Q
What are the 2 basic concepts of soil?
A
edaphology and pedology
5
Q
What is edaphology?
A
the study of soils as a medium for plant growth
6
Q
What is pedology?
A
the study of soils in relation to their environment
7
Q
What kinda science is soil science?
A
applied science
8
Q
What is porosity?
A
gives soil the ability to carry nutrients and minerals – also known as where “things” live
9
Q
What are the differences between soil and rocks?
A
soil is/has porosity, organic matter and is unconsolidated
10
Q
What are the 4 components that make up pedology?
A
atmosphere, biosphere, lithosphere and hydrosphere
11
Q
What are pedons?
A
the smallest volume (3D) that can be regarded as a “soil” – basic unit of soil (each have different cell forming factors)
12
Q
What are polypedons?
A
a contiguous group of similar pedons (used for mapping)
13
Q
What is a profile and what is one composed of?
A
a vertical slice through the soil (2D) – normally 1-100 cm and containing A, B and C horizons
A: surface
B: subsurface
C: parent material
14
Q
What are the 3 major integrated steps of soil formation?
A
- Accumulation of parent material – geologic mat on soil: due to wind, H20 and ice
- Effect of soil forming factors at larger scales
- Differentiation of horizons within the soil profile by soil forming processes
15
Q
What are horizon differentiations characterized as?
A
additions (aka inputs/illuviations), loses (aka exits/eluviations), transfers/translocations (movement of soil constituents within the profile and/or between horizons) and transformations (chemical weathering or of coarse OgM into decay resistant organic compounds)
16
Q
How long has soil been developping in Canada?
A
15,000 years
17
Q
How does the mode of transport/deposition affect soil parent materials?
A
alters texture and provides some common patterns of surface expression in the landscape
18
Q
What are the 2 types of soil parent materials?
A
Organic (from wetlands) vs mineral (transported or weathered bedrock)
19
Q
Where do soil parent materials come from?
A
Residual vs transported (formed in place vs moved by wind, H20 or ice)
20
Q
What are the 2 types of transported soil parent materials?
A
sorted (homogeneous particle size): low E deposition
unsorted (heterogeneous particle size): high E deposition
21
Q
What does alluvial mean? (modes of deposition of transported soil PM)
A
(moving water): high/low E — round rocks, sorted, fine texture
22
Q
What does marine mean? (modes of deposition of transported soil PM)
A
(tides): low to high E
23
Q
What does lacustrine mean? (modes of deposition of transported soil PM)
A
(standing water): low E – very fine texture, sorted, varves
24
Q
What does eolian mean? (modes of deposition of transported soil PM)
A
(wind): low E — sorted
25
What does glacial ice mean? (modes of deposition of transported soil PM)
(moraines/till): high E – unsorted, subangular (not perfectly round)
26
What does colluvial mean? (modes of deposition of transported soil PM)
(gravity): high E – unsorted, very angular
27
What are the 3 phases of horizontal soil morphology?
A: eluviation
B: illuviation
C: parent material
28
What are the 4 key soil characteristics?
Color: due to REDOXomorphic conditions and OgM additions
Texture: due to clay movement and nutrient/H2O retention
Structure: due to sodium content, clay loss/addition and OgM additions
Presence of carbonates: can help determine where horizons begin/end and tells about PM geology
29
What are REDOXomorphic conditions due to and what colours do they turn?
due to iron
Oxidized = orange
Less iron = blue/gray
30
What are mottles?
patches of orange on blue/gray background due to moisture content that's affected by seasonal saturation and/or extreme precipitation
31
What are the 3 components of soil colour?
Hue: spectral color
Value: the darkness (affected by OgM)
Chroma: intensity
32
What are the textures of soil particles (order)?
Soil = > or = 2mm
Rock = >2mm
Sand = 2-0.02mm
Silt = 0.02-0.002mm
Clay = < or = 0.002mm (2um)
33
What are soils primary particles?
sand, silt and clay particles
34
What is granular soil structure?
resembles cookie crumbs and is usually less than 0.5cm in diameter – found on surface horizons where roots have been growing (A - OgM addition)
35
What is blocky soil structure?
irregular blocks that are usually 1.5-5m in diameter (B - clay addition)
36
What is prismatic soil structure?
vertical columns of soil that might be a number of cm long – usually found in lower horizons (B - Na addition)
37
What is columnar soil structure?
vertical columns of soil that have a salt cap at the top – found in soils of arid climates (B - sodium addition)
38
What is platy soil structure?
thin, flat plates of soil that lie horizontally – usually found in compacted soil (A - clay loss)
39
What is single grained soil structure?
soil is broken into individual particles that do not stick together – always accompanies a loose consistence and is found in sandy soils (coarse texture - absence of glue)
40
What is hue?
dominant spectral colour (most mineral soils found to be somewhere between red-yellow)
Redox soils normally a blue-green colour
41
What is value?
degree of darkness (black = 0 to white = 10)
42
What is chroma?
the intensity of colour (0 = pastels to 10 = bright)
43
Where is hue and redox on the munsell wheel?
normally hue is 5R-5Y whereas redox is around 5B-5BG
44
What colour does oxidizes/gleyed iron yield?
Oxidized Fe3+ = bright red (= good drainage)
Reduced Fe2+ = gleyed colour (= poor drainage)
45
How does moisture/OgM affect value?
Increased moisture content = decreased value (gets darker)
Increased OgM content = decreased value (gets darker)
46
Lighter colour = ____ value?
Lighter = increased value
Light brown = value >6 with 1-3% OgM
Brown = value 4-5 with 3-5% OgM
Black = value <3 with >5% OgM
47
What are carbonates?
white mottles not associated with REDOX conditions
48
What is loam?
equal distribution of all particles (sand, silt and clay)
49
How does drainage affect colour?
If in drainage area, normally blue/gray due to REDOX conditions
50
What is clay?
Soil particle size =or<0.002mm
Kind of mineral (ilite, smectite, montmorillonite)
Textural class (>40% clay content)
Derived from PM
Clay is an important physical and chemical property due to high SA (makes soil sticky)
51
Eluviation vs illuviation of clay
Eluviation: lessivage = loss of clay
Illuviation: accumulation, leads to clay skins
52
What is a key characteristic of lacustrine freshwater lakes?
Have varves (inherited property) from PM deposition
Seasonal differences in water movement can influence particle deposition
53
What are the downsides to sand/silt and clay?
sand/silt = susceptible to erosion // clay = susceptible to compaction
54
What is structure?
Combo of primary particles (sand, silt and clay) into secondary structural units (peds or aggregates)
55
What are the 4 kinds of structure?
structure less, block-like, plate like and prism like
56
What is class?
size of aggregates (fine, medium and coarse)
57
What is grade?
can we see peds in the profile (weak, moderate or strong)
58
What is consistence?
stability of ped outside profile
Friable, loose or firm
Stickiness (when wet)
strength/resistance to deformation
59
What are the 4 types of glue?
1. Glue = clay (sticky)
drying/wetting cycles cause shrink/swell
Bt horizon: lessivage, slay skins (blocky)
2. Glue = OgM
Ah horizon: high biological activity (root microbes) – granular
3. No glue = Clay + Na+
Bnt horizon: dispersion of clay on top, deposition of salt, water erosion on sides (columnar)
4. No glue = none left
Ae horizon: loss of clay, thin horizontal peds (platy)
60
How do structural units develop?
Adhesive substances (glue)
Forces (copaction, swelling-wetting or freezing, bioturbation, etc.)
61
Genesis of texture and structure?
Texture: property inherited from the soil PM
Structure: forms in response to pedogenic processes
Soil structure = 2D
Soil texture = not inherited nor glued together, 1D particle
62
What is the influence of structure on soil performance?
Decrease: susceptibility to erosion and compaction
Increase: aeration, drainage, root growth (porosity) and microbial activity
63
What factors control processes and form soils?
Climate
Organisms
Parent material
Relief
Time
64
Factors affect what processes that form soils?
Additions: OgM, clay, iron oxides, salts
Loses: OgM, clay, iron oxides, salts
Translocation: OgM, clay
Transformations: OgM, minerals
65
What soils are formed from factors and processes?
Horizons
Colour
Texture
Structure
Carbonates
Biota
Mineralogy
Biogeochemistry
66
Which way do soils form?
down
67
What are principles of classification?
based on properties of soils that we can observe (such as colour, texture and structure)
Allows us to group soils into classes that reflect similar soil forming processes
Organizes soils on the basis of their common genesis
Character – processes – factors
68
What affects horizons?
Thickness
Colour
Texture
Structure
Consistency
Roots
Pores
69
What are the 5 parts of the soil classification hierarchical system (top of pyramid to bottom) and how many of each are there in Canada?
Order: 10 – differentiated based on the effects of the dominant soil forming processes (separated at this level based on the presence or absence of selected diagnostic horizons) – studying podzolic, solonetzic, chernozemic, luvisolic and brunisolic orders
Great group: 31 – strength of dominant process, major contribution of an additional process
Subgroup: 124 – arrangement of soil horizons – reflects conformity to the central concept of the great group – intergrading (gradation) towards another soil order – presence of a special horizon
Family: alot – dominant PM
Series: 600 – grouped by pedon with historic settler names
70
What is alluvial PM?
gravels, sands and/or silts deposited by moving water (rounded)
71
What is lacustrine PM?
fine sand, silt or clay deposited through particles settling out of standing water -- well sorted, possibly stratified and free of coarse fragments
72
What is eolian PM?
medium to fine sand and silts deposited by wind -- well sorted and free of coarse fragments -- some rounding
73
What is morainal PM?
heterogenous mix of particle sizes deposited by glacial ice -- unsorted with flecks of coal and siltstone
74
What is colluvial PM?
range of particles deposited by gravity -- often seen as talus cones at the base of cliff faces or mountain slopes
75
What is typically seen in the A horizon?
mineral horizon with eluviation and/or OgM
76
What is typically seen in the B horizon?
illuvial OgM, sequioxides or clay
77
What is typically seen in the C horizon?
unaffected by pedogenic processes except for gleying and accumulation of carbonates and soluble salts
78
ca
carbonate enrichment with more lime than in the PM
79
e
eluviation of clay, Fe, Al or OgM -- higher in colour when dry than B
80
f
amorphous material (esp. Al and Fe oxides combined with OgM)
81
g
gray colour and/or prominent mottling (shows permanent or periodic intense reduction caused by water)
82
h
enriched with OgM -- used with Ah or Ahe or Bh or Bhf
83
j
modifier of e, f, g, n, t or v to show a juvenile form of them (characteristics are evident but do not meet the specified limits of the suffix it modifies)
84
k
presence of carbonates by visible effervescence when dilute HCl is added
85
m
slightly altered by hydrolysis, oxidation or solution or all 3 to show change in color and/or structure
86
n
ratio of exchangeable Ca to Na is 10 or less -- must also have
- prismatic or columnar
- dark coatings on ped surfaces
- hard to very hard consistence when dry
87
p
disturbed by mans activities such as cultivation, logging or habituation (used with A and O)
88
s
with salts (incl. gypsum as crystals or veins)
- indicators of saline horizons can include surface crusts of salt crystals
89
sa
secondary enrichment of salts more soluble than Ca and Mg carbonates (more concentrated than PM)
90
ss
presence of slickensides (sheer surfaces formed when one soil mass moves over another often displaying unidirectional parallel grooves)
91
t
illuvial horizon enriched with silicate clay (often in B)
92
v
vertic horizon affected by argiliturbation -- disruption and mixing caused by shrinking and swelling of the soil mass
93
y
evidence of cryoturbation as manifested by disrupted and broken horizons
94
z
frozen
95
Who was the founder of soil sciences?
Vasiliy Dokuchaev: 1846-1903 – known for pedogenesis
96
What are common characteristics of chernozem?
97
What are common characteristics of luvisol?
98
What are common characteristics of solonetz?
99
How does precipitation affect OgM, vegetative biomass and pedogenesis?
100
What is the avg temperature and precipitation in edmonton?
0 and 400-600
101
Why is soil moisture different from precipitatiton?
due to run off and evaporation
102
Human ag activity is slowly turning soil into what?
chernozems
103
What affects carbon density?
agriculture, forestry, oil and gas
104
What are the 3 sizes of soil organisms?
micro, meso and mega
105
What is aspect?
the direction the slope faces
Can affect solar radiation
As water moves down it can lead the A horizon depth to increase
Elevation change of 1-4 meters makes a difference over 200 meters
106
What is relief?
the differences in height from place to place on the land's surface
107
What kind of soils do you find in grasslands?
chernozem and solonetz
108
What kind of soils do you find in a forest?
podzol, luvisol or brunisol
109
What is litter (L)?
organic horizon with leaves, twigs and woody material
110
What is fibric (F)?
organic horizon with partly decomposed OgM
111
What is humic (H)?
organic horizon with decomposed OgM
112
What is Of?
the least decomposed organic layer, containing large amounts of well preserved fiber (fibric layer)
113
What is Om?
intermediately decomposed organic layer containing less fiber than an Of layer and called the mesic layer
114
What is Oh?
most decomposed organic layer, containing only small amounts of raw fiber and called the humic layer
115
What 2 soils do you most often see together?
Chernozemic and Solonetzic
Together like glue, think han solo and chewbacca
Difference is salt content and structural features associated with salt (Bn in solonetzic second layer has more salt)
Cherno is continental, semi-arid to subhumid (cold and dry) – native grasslands and agriculture
116
What are the terms for time, climate, organisms, PM and relief in the study of soil genesis?
Time: chronosequence
Climate: climosequence
Organisms: biosequence
PM: lithosequence
Relief: toposequence
117
What are 2 main concepts for chernozem soils?
Leaching of calcium carbonates
PM: limestone
Weathers to form weak acid
Leaves calcium behind
Over 80% base saturation
Accumulation of Ogm
Grass vegetation, biomass below ground
Glue – granular structure
Foraging of plants for nutrients creates structure
<3.5 colour value (dark)
118
What are the great groups of chernozems?
Brown
Dark born
Black
Dark gray
119
What are the subgroups of chernozems?
Orthic (B)
Rego (no B)
Calcareous (Bc)
Eluviated (Bt)
Solonetzic (Bn)
Gleyed (Bg)
120
What are the T, C, O, PM and R of solonetzic order?
Time: 10-15K years
Climate: continental, semi-arid to subhumid
Organsms: vegetation dominated by native grasses
PM: fine texture, Na content must be high
Relief: bench lands to rolling hills
121
The toposequence of solonetzic soils is the same as chernozemic except...
Sodium rich PM (inherited)
Horizonation is a result of desalination (aka solodization)
Leaching sodium through the profile
Groundwater discharge
Sodium leaching accumulates in an area
Toe slope position
122
What are the 2 problems seen in solonetzic soils?
defloculation of clay and decreased aggregation due to sodium levels
123
What are the great groups of solonetzic?
Solonetz (same as order)
Solodized solonetz – has round topped columnar structure
Solod – no columnar structure
124
What are the subgroups of solonetzic?
Brown
Dark brown
Black
Gleyed
Dark gray
125
What are the 2 forms of structureless?
single grain and amorphous (coherent mass)
126
What are the types of block-like structure?
1. blocky (rectangular and flattened)
2. subangular blocky (oblique or subrounded)
3. granular (spheroidal and rounded vertices)
127
What are the types of plate like structure?
platy: horizontal planes more or less developped
128
What are the types of prism like structure?
prismatic (vertical faces well defined and edges sharp) and columnar (vertical medium columnar not sharp, may be flat, round or irregularly topped)
129
What is the order of canadian system of soil classification?
order, great group, subgroup, family, series
130
Characteristics of brunisolic soil?
- wide variety of climatic and vegetative conditions
- brownish Bm or Btj horizon
- melanic, eutric, sombric and dystric
131
Characteristics of chernozemic soil?
- developed under xerophytic or mesophytic grasses and forbs
- grassland forest transition vegetation
- cool, subarid to subhumid climates
- dark coloured surface
- Ah, Ahe, Ap + B or C of high base saturation
- brown, dark brown, black and dark gray
132
Characteristics of luvisolic soil?
- may have eluvial horizons (Ae) and must have illuvial horizons where silicate clay is the main accumulation porduct (Bt)
- develop under deciduous or mixed forest
- cool climate
- gray and gray brown
133
What defines organic soils and what are its GGs?
saturated most of the year, more than 17% organic carbon, GGs are fibrisol, mesisol, humisol and folisol
134
Characteristics of Podzolic soils?
- coniferous forests
- Bh, Bhf or Bf
- Al, Fe and Ogm have accumulated
- acidic
- humic, ferro-humic and humo-ferric
135
Characteristics of solonetzic soils?
- grass/grass forest vegetative cover
= semiarid to subhjumid climates
- may have stained brownish solonetzic (Bn or Bnt)
- Saline C
- surface may be Ap, Ah, Ahe and/or Ae
- solonetz, solodized solonetz, solod and vertic solonetz
136
Diagnostic horizon for Chernozerm?
Ah
137
Diagnostic horizon for solonetz?
Bn/Bnt
138
Diagnostic horizon for luvisol?
Bt
139
Diagnostic horizon for Podzol?
Bh, Bhf, Bf
140
What are T,C,O,PM and R for luvisolic order?
Time: 10-15K years
Climate: continental, subhumid to humid (MAT >0 and MAP > 700mm)
Organisms: vegetation dominated by forests
PM: fine-medium texture, glacial moraine and glacial fluvial
Relief: rolling hills to steep
141
What are luvisols GGs?
Gray and Gray brown
142
What are luvisols SGs?
orthic, brunisolic, podzolic, vertic, fragic, gleyed and dark
143
What are the genetic concepts for luvisols?
PM is fine to medium texture and must have clay
Leaching of carbonates occurs like chernozem only faster
Increased water percolating
Loss of base cations (Ca, K, Ca and Mg)
Acidification of surface horizon
144
What are T,C,O,PM and R for podzolic order?
Time: 10-15K years
Climate: humid (more precipitation than AB – typically like BC/QC)
Organisms: vegetation dominated by forests (conifer)
PM: coarse textured (sands)
Relief: flat, rolling hills and steep
Found in eastern CA, canadian shield, granitic material, shallow depth to bedrock (NO PODZOLS IN AB) ***associated with forests, sandy PM and MAP>700mm (east n west)
145
What are podzols GGs?
humic (Bh): Bh over 10cm, more than 5% OgM and less than 0.3% Fe
ferro humic (Bhf and Bf): Bhf>10cm, 0-5% OgM and 0.3-0.5% OgM
humo ferric (Bf): less than 1% OgM and >0.5% iron
146
What are podzols SGs?
orthic, luvisolic and gleyed (more but were not focusing on them)
147
What are the genetic concepts for podzols?
Acidic PM
Canadian shield
Granitic
Alkaline PM becomes acidic overtime due to climate and vegetation
Coarse texture
Sand, sandy loam and loam
Well drained
conifer/heath vegetation
Produces acidic litter (decomposition increases protons and leeches base cations out of the soil profile)
Podzolization
Eluviation of iron and aluminum oxides and OgM from A horizon into the B horizon resulting in Bf, Bh or Bfh
148
What is orstein?
cementation, from iron and aluminum oxides (causes hard soil aggregates)
149
What are T,C,O,PM and R for brunisolic order?
“Not enough” soil category – not enough time/development to be another soil
Time: 10-15K years
Climate: sub-humid to boreal
Organisms: vegetation dominated by forests
PM: fine-coarse
Relief: flat, rolling or steep
(can be found just about anywhere)
150
What are the genetic concepts for brunisolic order?
Not enough temperature
MAP <0 degrees
Commonly found in mountains/cold boreal forests
Low biomass due to slow decomposition (low OgM)
Not enough time
151
What are brunisols GGs?
Eutric (pH>5.5 and has no Ah)
Melanic (pH>5.5 and has Ah)
Sombric (pH<5.5 and has Ah)
Dystric (pH<5.5 and has no Ah)
152
What are brunisols SGs?
orthic, (+lots more… such as podzol, luvisol, gleyed…)
153
Which orders are associated with forests?
luvisols, podzols and brunisols
154
What are some details about soil mapping in AB?
Started in the 1960s
Standardized soil classification
Introduction of soil map units
Canadian land inventory (CLI) developed
Around 40 soil survey reports throughout the province
Last government sponsored report in the early 1990s
Helps with resource development
For private sector pedologists
155
What do environmental assessments determine?
EIA: environmental impact assessments (forestry)
PDA: pre disturbance assessments (oil and gas)
Baseline studies to determine land capability
156
What does terrain classification include?
includes both topographic form, PM interpretations and geomorphic processes (active and inactive)
157
What are some tools used for soil mapping?
Stereoscope: a historic tool that uses airphotos and eyepiece to create a 3D model
Draw lines with a grease pencil or marker on photos or clear mylar and it allows you to measure polygons with a panimeter
GIS Systems: used for pre-field planning and post field analysis – digital mapping used to create polygons and stats for interpretation (uses vector and raster data)
3D digital mapping: uses additional software added to a GIS platform (ex. DiAP, Dat/em, PurView) – digital stereoscopic models are build with overlap just like old stereoscopes (also requires special hardware computer screens and 3D glasses)
LiDAR (light detection and ranging): laser based system that produces highly accurate digital elevation models (DEMs)
Laser swath scans the surface and measures rates for return of the different signals
Captures all elements between the sensor and the earth's surface and produces 2 forms of output: full earth and bare earth
158
What are the 3 main steps for soil mapping?
Create polygons
ID key features
Report soil types
***stratification and identification
159
What is scale?
ratio distance on map to distance on the ground (same unit) – ex. 1:500,000 = small scale whereas 1:10,000 = large scale (need a large piece of paper to map it)
160
What is basis for stratification?
diagnostic criteria where the poly pedons on the landscape depend on scale
161
What is basis for ID?
method of surveying however is changing with digital technology
Grid: simple (don’t need skilled interpretation) and the proportions of features are within grid cells
Physiographic: based on terrain analysis, aerial photos, satellite images, LiDAR, GIS and 3D viewing and internet resources (AGRASID)
162
White zone vs Green zone
White zone = agriculture and green zone = forestry – oil and gas throughout
163
What is AGRASID?
First use of digital mapping in Alberta (old reports combined and digitized)
Uses existing soil survey reports (compiled data to standardized soil series into one database)
Introduced the soil landscape model
Map unit utilizes a soil symbol and soil model number to identify polygons
Soils mapped at 1:10,000 scale (large)
164
