Soils and Land Use
Quick review of learning objectives
Things you MUST know
An introduction to urban soils
Questions
SALU: Learning Objectives
Soil Conservation and Land Use Management
• Understand why soils are a vital (and essentially nonrenewable) natural resource that must be managed properly in
order to sustain human society.
• Compare different land uses and conservation practices and
their impacts on soils, with particular emphasis on agriculture
and food production.
• Understand how soil management is integral to maintaining
clean water and a healthy aquatic environment.
SALU: Learning Objectives
Chemical Properties of Soil and Soil Fertility
• Understand how soil fertility reflects the overall chemical,
physical, and biological conditions within a given soil.
• Understand the concept of micronutrients and macronutrients
as they relate to soils and plant nutrition.
• Identify roles and benefits of organic matter in soils.
SALU: Learning Objectives
Physical Properties of Soil and Soil Formation
• Understand basic soil forming processes and the factors
affecting them.
• Understand the concept of soil parent material and how
different parent materials can affect soil properties.
SALU: Learning Objectives
Physical Properties of Soil and Soil Formation
• Be able to identify common soil horizons and soil features and
use this information to interpret soil properties and limitations
for land use (e.g., texture, colour, structure, organic matter
content, stoniness, drainage class).
• Be able to use soil survey maps and related information to
make interpretations about soil limitations, opportunities, and
appropriate land use.
SALU: Things You MUST Know
…or must begin to understand and appreciate.
• The main soil development processes that produce
different soil types.
• The factors that influence these development
processes.
• How to “read” the soil profile (or interpret survey
information).
SALU: Things You MUST Know
The main development processes that produce different
soil types:
•
•
•
•
Weathering
Leaching related processes
Organic matter incorporation and movement
Gleying related processes
(Additions / Losses / Transformation / Translocation)
SALU: Things You MUST Know
The factors that influence these development processes:
s = f (cl, p, r, o, t)
Soil (s) is a function (f) of five main factors (cl, p, r, o, t).
These five factors influence (more or less) the main
formation processes to “produce” the soil you see.
What do these symbols (cl, p, r, o, t) stand for?
How to “read” the soil
profile
What are the horizons and
features of this soil profile?
How did these horizons
develop (processes)?
Why did this soil develop
this way at this location
(factors)?
How can this information be
interpreted for land-use?
Example… Post-Juan Clean-up at Point Pleasant Park
PPP soils are high in silt and often shallow to bedrock.
What’s the main “damage” hazard associated with these soils?
Urban Soils
Image from: HRM Urban Forest Master Plan
Urban Soils
Urban soils generally run the gamut of slightly altered
natural soils, to highly disturbed natural soils, to
completely anthropogenic soils.
The added challenge in urban soil assessment and
interpretation (versus natural soils) is you must also
consider “urban soil” features.
Urban Soils
Some common features of urban soils versus natural
soils (though not always the case):
- Higher concentrations of heavy metals (e.g. Pb, Cr, Zn).
- Sometimes higher concentrations of calcium.
- Variable drainage conditions often with a disconnect between
topography and drainage.
- Highly variable bulk density values.
- Variable surface conditions affecting infiltration and hydrology.
Urban Soil Classification
Recall…
5 main factors that influence soil development:
s = f (cl,p,r,o,t)
For urban soils, some are suggesting adding a sixth
factor
s = f (a,cl,p,r,o,t)
Urban Soil Classification
Some larger cities have started to develop urban
landscape and soil classifications akin to those
produced for natural landscapes and soils.
These classifications follow similar protocols used in
“natural” soil surveys, but integrate features and
conditions unique to the urban setting.
NYC Soil Classification
New York City Soil Survey Staff. 2005. New York City Reconnaissance Soil Survey. United States Department of
Agriculture, Natural Resources Conservation Service, Staten Island, NY.
Greenbelt - North Meadow
complex:
Nearly level to gently sloping areas of
urbanized till plains that have been
filled with natural soil materials for
parkland; a mixture of well drained
and moderately well drained
anthropogenic soils; located in Central
Park in Manhattan.
NYC Soil Classification
Deerfield-Wareham-Pavement
& Buildings complex:
Nearly level to gently sloping areas of
outwash plains that are partially
wooded and partially developed; a
mixture of moderately well drained
and poorly drained sandy outwash
soils, with more than 15 percent
impervious pavement and buildings
covering the surface; located in
western Staten Island.
NYC Soil
Classification
Typical Soil Profile:
A 0 to 3 inches – dark grayish brown (10YR 4/2)
fine sand; single grain; loose; 1 percent gravel;
extremely acid.
Bigapple Series
E 3 to 8 inches – brown (10YR 5/3) fine sand;
single grain; loose; 1 percent gravel; extremely
acid.
Parent Material: Sandy
dredge deposits, greater
than 40 inches deep
Bw 8 to 20 inches – yellowish brown (10YR
5/4) stratified sand; weak medium subangular
blocky structure; very friable; 1 percent gravel;
extremely acid.
Landform: Anthropogenic
fill areas near coastal
waterways
C1 20 to 28 inches – yellowish brown (10YR
6/4) and grayish brown (10YR 5/2) stratified
sand; massive; very friable; 5 percent gravel;
very strongly acid.
C2 28 to 60 inches – grayish brown (10YR 5/2)
and gray (10YR 5/1) stratified sand; massive;
very friable; 2 percent gravel; very strongly
acid.
NYC Soil
Classification
Typical Soil Profile:
A 0 to 3 inches – dark grayish brown (10YR 4/2)
fine sand; single grain; loose; 1 percent gravel;
extremely acid.
E 3 to 8 inches – brown (10YR 5/3) fine sand;
single grain; loose; 1 percent gravel; extremely
acid.
Bw 8 to 20 inches – yellowish brown (10YR
5/4) stratified sand; weak medium subangular
blocky structure; very friable; 1 percent gravel;
extremely acid.
C1 20 to 28 inches – yellowish brown (10YR
6/4) and grayish brown (10YR 5/2) stratified
sand; massive; very friable; 5 percent gravel;
very strongly acid.
C2 28 to 60 inches – grayish brown (10YR 5/2)
and gray (10YR 5/1) stratified sand; massive;
very friable; 2 percent gravel; very strongly
acid.
NYC Soil
Classification
Inwood Series
Parent Material:
Construction debris and
rubble mixed with natural
soil; greater than 75
percent coarse fragments
Landform: Anthropogenic
urban cut and fill plains
Typical Soil Profile:
A 0 to 6 inches – yellowish brown (10YR 5/4) gravelly
sandy loam; weak fine platy structure; friable; 10
percent gravel-sized artifacts and 5 percent gneissic
gravel; neutral.
Bw 6 to 12 inches – yellowish brown (10YR 5/4) very
gravelly sandy loam; weak fine subangular blocky
structure; friable; 35 percent gravel-sized artifacts
and 5 percent gneissic gravel; neutral.
C1 12 to 16 inches – yellowish brown (10YR 5/6) very
gravelly sandy loam; massive; friable; 35 percent
gravel-sized artifacts and 10 percent gneissic gravel;
neutral.
C2 16 to 65 inches – yellowish brown (10YR 5/6)
extremely stony sandy loam; massive; friable; 80
percent stone-sized artifacts (concrete, asphalt,
wood, metal) and 10 percent gneissic stones;
neutral.
NYC Soil
Classification
Typical Soil Profile:
A 0 to 6 inches – yellowish brown (10YR 5/4) gravelly
sandy loam; weak fine platy structure; friable; 10
percent gravel-sized artifacts and 5 percent gneissic
gravel; neutral.
Bw 6 to 12 inches – yellowish brown (10YR 5/4) very
gravelly sandy loam; weak fine subangular blocky
structure; friable; 35 percent gravel-sized artifacts
and 5 percent gneissic gravel; neutral.
C1 12 to 16 inches – yellowish brown (10YR 5/6) very
gravelly sandy loam; massive; friable; 35 percent
gravel-sized artifacts and 10 percent gneissic gravel;
neutral.
C2 16 to 65 inches – yellowish brown (10YR 5/6)
extremely stony sandy loam; massive; friable; 80
percent stone-sized artifacts (concrete, asphalt,
wood, metal) and 10 percent gneissic stones;
neutral.
Soils and Land Use
Thank you.
Kevin Keys, RPF, P.Ag.
Nova Scotia Natural Resources
P.S. The world needs more soil scientists,
consider a career in soils!
Questions?