EESA01 Lecture7-2011-compressed

EESA01 Lecture7-2011-compressed - EESA01
Lecture
7


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Unformatted text preview: EESA01
Lecture
7
 Water
Pollu3on
and
Soil
Science
 October
31,
2011
 Lecture
7
–
Water
Pollu3on
and
Soils
 1
 Water
Pollu3on
 •  Pollu%on:
the
release
into
the
 environment
of
maBer
or
energy
that
 causes
undesirable
impacts
on
the
health
 and
well‐being
of
humans
or
other
 organisms.

 •  Point
source:
emission
of
pollu3on
from
 discrete,
easily
recognized
loca3ons.

 •  Non‐point
source:
emission
of
pollu3on
 from
mul3ple
cumula3ve
inputs
over
 large
areas.

 Lecture
7
–
Water
Pollu3on
and
Soils
 2
 Point
vs.
Non‐Point
Source
 Pollu3on
 Lecture
7
–
Water
Pollu3on
and
Soils
 3
 The
solu3on
to
pollu3on
is
NOT
 dilu3on,
it
is
PREVENTION
in
the
first
 place.
 Lecture
7
–
Water
Pollu3on
and
Soils
 4
 Red
Mud
in
Hungary!!
 http://www.youtube.com/watch?v=xEMWh6EjJoY Lecture
7
–
Water
Pollu3on
and
Soils
 5
 Industrial
Issue:
Aluminum
 Produc3on
 ALUMINUM PROCESSING Lecture
7
–
Water
Pollu3on
and
Soils
 6
 Red
Mud
and
pH
 Lecture
7
–
Water
Pollu3on
and
Soils
 7
 Soil
is
a
CRITICAL
RESOURCE
 SOIL
IS
AN
ABSOLUTELY
CRITICAL
RESOURCE
 •  Decline
and
fall
of
the
Mesopotamian
culture
(salt)
 •  Failure
of
Aztec
culture
 CANADA:



 •  13%
cropland
 •  54%
forests
and
woodlands

 CRITICAL
FUNCTIONS:
 •  Agriculture/support
of
plants


FOOD!!!
 •  Soil
carbon
storage
 •  Ecosystem

 Lecture
7
–
Water
Pollu3on
and
Soils
 8
 Soil
is
a
“System”
 •  Complex
mixture
of
 organic
and
inorganic
 component
and
full
of
 various
organisms:

 –  –  –  –  Lecture
7
–
Water
Pollu3on
and
Soils
 Bacteria
 Pro3sts
 Fungi
 Invertebrates
such
as
 earthworms
 9
 How
Does
Soil
Form?
 Lecture
7
–
Water
Pollu3on
and
Soils
 10
 How
To
Get
Unconsolidated
 Material

 WEATHERING
 –  PHYSICAL

(MECHANICAL)
 •  GLACIERS,
TEMPERATURE
CHANGE,
FREEZING
OF
WATER
 –  CHEMICAL

 •  •  •  •  DISSOLUTION
IN
ACIDS
(RAINFALL)

 CARBONIC
ACID–
H2CO3
 PLANT
ORGANIC
ACIDS

 BACTERIA,
WORMS
 Lecture
7
–
Water
Pollu3on
and
Soils
 11
 Soil
Forming
Factors
 12
 Soil
Characteriza3on
 1.  Colour

largely
indicates
composi3on
(i.e.,
iron
 or
organic
maBer
content)
 2.  Texture

controlled
by
size
of
par3cles
 3.  Structure

indicates
the
organiza3on
or
 “clumpiness”
of
soil
 4.  Chem:pH

1‐14
scale;
low
=
acid;
high
=
alkaline
 Canadian
System
of
Soil
Classifica%on
 Orders:
Brunisolic,
Chernozemic,
Gleysolic,
Cryosolic,
 Luvisolic,
Organic,
Regosolic,
Podzolic,
Solonetzic,
 and
Ver3solic
 Lecture
7
–
Water
Pollu3on
and
Soils
 13
 Soil
Texture
 Lecture
7
–
Water
Pollu3on
and
Soils
 14
 Soil
Chemistry:
Ca3on
Exchange
 •  Principal
means
by
which
plants
gain
nutrients
 like
K+,
Mg2+,
Ca2+,
other
ca3ons
 •  More
nega3vely
charged
surfaces
on
soil
means
 more
posi3vely
charged
ions
can
be
held
 •  Exchange:
plant
roots
donate
H+
to
soil
in
return
 for
ca3on
nutrients
 •  Ca%on
exchange
capacity
(CEC)
expresses
a
soil’s
 ability
to
hold
onto
ca3ons
(i.e.,
not
to
be
leached
 out)
 •  CEC
is
a
thus
very
important
fer3lity
parameter
 Lecture
7
–
Water
Pollu3on
and
Soils
 15
 Ca3on
Exchange
Capacity
 Lecture
7
–
Water
Pollu3on
and
Soils
 16
 Soils
are
Fragile
 Lecture
7
–
Water
Pollu3on
and
Soils
 17
 We
Cannot
Con3nue
to
Extensify
 Actually,
we
are
losing
arable
cropland.
 •  Loss
since
Agricultural
Revolu3on:

 –  –  •  •  4.3
x
106
km2
=
1/3
current
global
cropland
 Current
rate
of
loss
=
200,000
km2
yr‐1
 Loss
due
to
urban‐industrial
sprawl

around
Toronto,
for
 instance
 Loss
due
to
soil
erosion


EVERYWHERE!
 Major problem: not all land is arable •  Land Capability Classification: –  Class 1 through 8 essentially go from great farmland to land of little use. Lecture
7
–
Water
Pollu3on
and
Soils
 18
 Class
1
Land:
Potatoes
 Lecture
7
–
Water
Pollu3on
and
Soils
 19
 Class
1
Land:
Crop?
 Lecture
7
–
Water
Pollu3on
and
Soils
 20
 Class
2
Land
 Lecture
7
–
Water
Pollu3on
and
Soils
 21
 Class
5
Land
 Lecture
7
–
Water
Pollu3on
and
Soils
 22
 Class
7
Land
 Lecture
7
–
Water
Pollu3on
and
Soils
 23
 Soil
Degrada3on
Problems
 Ideal
Soil:
loamy
mixture
with
neutral
pH
that
is
 workable
and
can
hold
nutrients
 Increasingly,
produc3vity
is
being
limited
by
human
 influences
on
what
used
to
be
GREAT
cropland.

 •  •  •  •  Erosion Desertification Salinization Waterlogging Lecture
7
–
Water
Pollu3on
and
Soils
 •  Nutrient depletion •  Structural breakdown •  Pollution 24
 Biggest
Issue:
SOIL
EROSION
 •  All
climate
and
soil
types
 •  Most
agricultural
techniques
increase
 erosion
rates
by
10‐100
X
“natural”
rates
 •  Agents
of
erosion
 1.  Wind:
flat,
treeless
terrain

exposure;
 dependent
on
texture
 2.  Water:
slope
and
rainfall
rates
are
cri3cal;
 increased
surface
runoff
causes
great
erosion
 Lecture
7
–
Water
Pollu3on
and
Soils
 25
 26
 27
 Drought
x
Wind:
The
“Dust
Bowl”
 And then… The grasshoppers came. Lecture
7
–
Water
Pollu3on
and
Soils
 28
 Soil
Conserva3on
&
Management
 Lecture
7
–
Water
Pollu3on
and
Soils
 29
 Soil
Conserva3on
&
Management
 Agroforestry: specific type of intercropping; lots of benefits (easier moisture management, return of litter as nutrients, shade, increased biodiversity). Lecture
7
–
Water
Pollu3on
and
Soils
 30
 Benefits
of
No‐Till
Farming
 31
 Conserving
Soil
=
Feeding
 Ourselves
 •  To
feed
our
burgeoning
popula3on
(10‐12
 million
by
2050),
we
will
require
more
FOOD
 and
the
base
of
all
food
is
grown
(plants;
 autotrophs).

 •  Overpopula3on
or
“consump3on
 overpopula3on”?
 •  2000
‐
OECD
countries
 •  •  •  •  
 
 
 
 
 
 
 
 20%
of
popula3on
 75%
of
produced
energy,

 61%
of
meat,

 42%
fresh
water
 Lecture
7
–
Water
Pollu3on
and
Soils
 32
 The
“Green
Revolu3on”
 Started
1940’s
 Running
out
of
arable
land
 Solu3on

get
more
out
of
each
unit
of
land
 How?
Via
technologies
that
increase
crop
 yields.
 •  Involves
“intensive
or
industrialized
 agriculture”
 •  Not
always
environmentally
sound
 (surprise?)
 •  •  •  •  Lecture
7
–
Water
Pollu3on
and
Soils
 33
 Industrialized
Agriculture
 Several
key
elements:

 1.  Selec%ve
breeding;
monocultures
 2.  Pest
control
 3.  Soil
nutrient
enhancement
 4.  Irriga3on

 5.  Mechanized
plan3ng
and
harves3ng
 6.  Large
energy
(fossil
fuel)
and
material
 inputs
 7.  Use
of
produce
for
other
than
ea%ng
(fuel)
 Lecture
7
–
Water
Pollu3on
and
Soils
 34
 ...
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