soil science lab 3 henna
pdf
School
University of Guelph *
*We aren’t endorsed by this school
Course
2060
Subject
Geography
Date
Jan 9, 2024
Type
Pages
7
Uploaded by MagistrateAtomHedgehog23
Lab
#
3
Water
in
Soil
Recommended
Reading:
Weil
and
Brady,
2017:
The
nature
and
properties
of
soils.
15"
ed.,
Chapters
5
and
6
Digging
into
Canadian
Soils
114-116,
118-132
Part
1.
Water
Content
Use
the
data
provided
in
table
1
to
calculate
the:
Mass
of
water
in
each
soil,
volume
of
water,
mass
based
water
content
(sometimes
called
gravimetric
water
content)
(0m),
Volumetric
water
content
(0v),
depth
equivalent
water
content
in
the
S0
cm
depth
of
each
soil
(Dw),
soil
bulk
density
(BD),
soil
pore
space
ratio
(PSR),
and
the
percentage
of
the
pore
space
occupied
by
water.
For
each
calculation
provide
your
rough
work
for the
calculations
on
one
of
the
soils
and
plovide
your
answers
in
table
2
below.
Remember
that
the
particle
density
will
remain
constant
at
2.65
g
cm™,
a)
Table
1
Data
on
soil
cores
for
use
in
calculation
in
part
1
a.
Core
#
Wet
weigh
of
soil
(g)
Dry
weight
of
soil
(g)
Volume
of
soil
(cm?)
1
178
126
125
2
200
165
125
3
225
175
125
Table
2
Mass
of
|
Volumeof
|
©®m
|
Ov
|
Dw
BD
PSR
|
%
of
pore
space
water
(g)
|
water
(cm®)
@)
|
)
|
ewem
|
(@em)
|
()
filled
with
water
1
523
52em®
|
Yl
7|
UVE|
20um]|
1.0
gw's
627/
66/
2
3Sg
S
om®
204|264
M
um
{3
(jum,
RILA
Sb
%
,
.
3
.
.
B
509
|
SO
om?
[297]U07
[200m[l4
glT]|
g7s
|
'
:
PSR
=
|-(1
qum’/2.65
)
Core
\:
Om
=
My
Ms
Dw
=
03)
(Pp)
=1-03
65
ger,
"
MH%L*
—MJ'Z
=529/1269
o)
(5D
o)
=0.bZ
xi00l
=\7%4-
12
=
7
N
3
_
oMl
xipo7
—200m
=
b2
{
=521
-
UL
BP=
Ms/\o
"
7.
pore
Spoce
=
Bv
/05%
—1\2bg
/1250m
=
a4l
)
=
Mw
/Dy
Oy
=V
/Ny
*\03»‘
0.
/:.6
-—
e
O-
b
’525/'
z
§20m/125
o
bt
7
z
52
o’
=0l
x
1007
]
=
Mt/
Scanned
with
CamScanner
Part
2:
Soil
water
potential
at
equilibrium
a)
Assuming
equilibrium,
determine
the
value
of
yn
and
its
components
(Wm,
yp
and
yg)
at
points
A,
B
and
C
in
the
above
diagram.
Express
the
potentials
in
units
of
cm
of
water
in
table
3.
Figure
|
soil
water
potential
diagram
stnarac
b
Soil
surface
30cm
y
8
Groundwater
table
65
cm
Cc
Table
3
soil
water
potential
at
equilibrium
using
position
“B”
as
the
gravitational
reference
POINT
Potential
A
(at
surface)
B
C
Ve
e
0
S
em
Ym
~
30
um
0
i
Ve
30
um
0
-65
o
Yn
Yh&\’j-l—
Y,\:30+L'3D):
0
\Qh.;
0-0=0
\thwa*‘v?:
,bi*bf;b
b)
Currently
in
figure
1
the
gravitational
reference
point
is
given
at
position
“B”
(the
water
table).
The
gravitational
reference
point
could
however
be
placed
anywhere
in
the
soil
profile
as
it
is
just
a
measure
of
the
relative
gravitational
energy.
Move
the
gravitational
reference
point
to
position
“A”
and
determine
the
value
of
yu
and
its
components
(Wm,
Wp
and
yg)
at
points
A,
B
and
C
in
the
above
diagram.
Express
the
potentials
in
units
of
cm
of
water
in
table
4.
Table
4
soil
water
potential
at
equilibrium
using
position
“A”
as
the
gravitational
reference
POINT
Potential
A
B
C
Ve
0
300m
as
om
Ve
0
el
—
Ve
D
-0
-
a5
¢
Wi
0
¥=Wg+¥p
>
-30430=0
[y,
=VYy+
Yp=
-95
+25=0
relative
values
between
positions
stays
the
same.
¢)
Make
note
that
even
though
the
absolute
values
of
yi
changed
in
table
3
and
table
4
that the
Scanned
with
CamScanner
Part
3
Soil
water
potential
at
non-equilibrium
In
non-equilibrium
condition
soil
matric
potential
cannot
be
determined
based
on
the
position
relative
to
the
water
table.
As
such
the
matric
potential
must
be
measured
at
each
of
the
desired
positions
in
a
soil.
Tensiometers,
which
measure
metric
potential,
were
installed
at
four
different
depths
(0,
10,
30
and
60
cm
below
the
soil
surface)
in
a
soil
profile.
On
three
different
days
(day
1,
3
and
10)
readings
of
ym
(in
cm
H20)
are
obtained.
The
data
are
presented
below
in
Table
5.
1.
a)
Using
position
A
in
table
S
as
the
gravitational
reference
point,
complete
table
5
by
filling
in
values
for
yg
and
yn
and
indicate
in
the
fourth
column
for
each
day
whether
the
water
is
flowing
upward
()
or
downward
(})
or
is
at
a
standstill
(0)
between
adjacent
positions
(ie
between
position
“A*”
and
“B”,
“B”
and
“C”
etc.).
e.g
A
water
flow
is
from
1
point
B
to
point
A
B
Table
5
Non-equilibrium
soil
hydraulic
potentials.
Day
1
Day
3
Day
10
Depth
Ym
Ve
[vao
[T
[VYm
Ve
|wn
[T
[Vm
ve
[wn
|1
(cm)
!
l
l
0
0
0
0A
20
[©
|70
4|
s
fo
|-
L
|40
|0
s
B
10B
60
|0
|7°
2|2
.10
|-3S
v
30
|no|-40
.
30C
g0
|0
=50
LB
[oles
.
a0
|-0|-5©
.
60
D
300
|-‘oe|-Ho0
320
|-100|-420
250
|-\bo|
-350
¢)
What
can
you
say
about
the
most
likely
weather
pattern
during
this
ten-day
period?
Wader
i
mMovag
in
this
ron
egaliprivm
soil.
The
hydrewvtic
potenbal
ot
A
ond
B
horizon
s
higher
on
Da
3,
inditchng
thot
dhe
s3U
is
more
sedveetated.
™S
means
¥
most
\Yely
rained
on
day
\,3
of
sust
on
doy
3.
Twe
\uoderis
iS
olso
moving
domnard
on
Day
3,
thdieoting
o
grecder
volume
g
SR
Greater
hy
drouic
pokential.
A
and
B
horizon
Wave
lower
k;gdrow\ic
?o'}on"ha\
on
o
(0
Yhen
3,06
0
resnt
dhe
soll
has
dried
o
sver
Kt
ot
Cvms
o
higner
ydmulic
potenkal
becavie
potor
has
flovied
down
after
the
vain
on
Pay
10
d)
In
this
case
(table
5),
explain
why
was
the
pressure
potential
(yp)
not
determined?
‘
Pre
ssure
folrm’ria\
s
not
dedormined
vecone
-here
1S
e
roim*m\.
“the
sol
wos
eing
measured
ot
@&
non
-
equiiorivm
stede,
s,
dhere
tond
not
have
peon
o
Pressert
gotential.
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Part
4.
Available
Water
a)
Compare
the
moisture
characteristic
data
for
the
following
3
soils
(figure
2)
and
complete
table
6
assuming
the
soil
is
uniform
in
texture
and
structure
to
50
cm
soil
depth.
To
determine
the
volume
of
water
per
hectare
in
table
6
multiply
the
depth
of
available
water
in
meters
by
the
surface
area
of
1
hectare
(10000
m?).
Also
remember
that
there
are
1000L
in
1
m®
of
water.
Figure
2
water
release
curves
of
3
soils
for
use
in
Part
4
a.
60
j—
-
50
_—
40
\-—————+—+++1
;
30
20
10
Soil
Water
Content
0v
(%
m3
m3)
Matric
Potential
¥m
(bars)
Y
Table
6
determination
of
plant
available
water
from
figure
2
Water
Water
Plant
available
|
depth
of
available
|
Volume
(L/ha)
of
content
(Ov)
|
content
(6v)
|
water
content
|
water
in
top
50
water
plant
at
Field
Cap.
|
Wilting
Point
|
(6v)
cm
of
soil
available
in
top
D=(6)
(DV)
50
cm
of
soil
207
-(0.20)
50
=100m\
=,
00O
o7
(030X
50>
(S
om
V=
1,
SO0
yn®
Isoil
1
|
45
7
257
lsatz
g
7
&7
M.S
%
£(0.145)
(SDum)
=73
e
V=130
o
soil3
|
\
&7
35
/.
"
V(o)
(5A)
@
Vo
=
(D)
(S
A
BNz
WM
=
(0.10v)
(10000
)
(0.
15
(10000)
~(0.013w)
(10000r)
=
1000
™
=
(500
yn’
=730
m®
Scanned
with
CamScanner
Part
5.
Water
Movement
in
Saturated
Soils
In
class
we
discussed
Darcy’s
experiment.
Figure
3
gives
a
representation
of
an
experiment
to
determine
the
flux
rate
of
water
coming
through
a
soil.
Figure
3
Darcy’s
experiment
example
to
be
used
to
complete
table
7
and
8
"
Water
f
R
10cm
|
|
f
12cm
o
Ref
point
b
Yoy
0o
[}
a)
Determine
the
hydraulic
potential
(wh)
at
both
point
A
and
B
represented
in
figure
2.
Present
the
data
in
table
7
Table
7
hydraulic
potential
for
the
experiment
indicated
in
figure
3
Position
in
figure
2
Potential
A
B
Yp
0
om
0
Ym
/
0
Ve
12
um
0
Yh
22
om
0
b)
Use
the
information
you
determined
in
Table
7
and
the
information
in
figure
3
to
determine
for
each
of
the
soils
in
table
8:
the
flux
rate
of
water
(Jw)
(equation
below),
the
change
in
hydraulic
potential
(Awh)
(from
table
7),
and
the
hydraulic
conductivity
(k)
(equation
below)
and
record
the
information
in
table
8.
Be
sure
to
show
your
work.
Scanned
with
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Table
8
presentation
of
results
for
Part
5
b.
Volume
of
Flux
rate
of
water
(Jw)
water
collected
v
(Vw)
=5
110
cm?
60
seconds
:
=25CE
(0o3foms!
60
seconds
35cm’
Part
2
Water
movement
in
unsaturated
soils
Watch
the
following
video
that
describes
water
movement
in
soils.
https://www.youtube.com/watch?v=DmTNFIEc2VA
and/
have
a
look
at
the
displays
in
the
lab
(note
they
show
the
same
thing
as
the
video)
a)
At
approximately
three
minutes
10
seconds
in
the
video
(3:10)
there
is
a
demonstration
of
capillary
rise
use
two
glass
plates.
They
are
separated
on
one
site
and
clamped
directly
together
on
the
other
to
represent
a
range
of
pore
size
from
large
on
the
open
side
to
very
small
on
the
other
side.
Examine
the
wedge
capillary
on
the
demonstration
table
and
the
height
of
rise
above
the
free
water
surface
at
the
closed
edge
of
the
wedge.
If
the
water
on
the
edge
of
the
glass
that
was
closed
together
was
drawn
up
to
a
total
hight
of
20
cx+
cm,
use
the
following
equation
calculate
the
theoretical
radius
of
the
pore
at
the
edge
of
the
wedge.
0.15
0.15
h=
r
Y=
h
-3
W=200m
'
o
Theoebcal
ragivs
is
7.5e
“om
or
o015
0-0075um
200m
-3
=
7.5€
un
b)
Once
again
from
the
video,
describe
what
happened
when
water
was
moving
through
a
non-saturated
loam
textured
soil
and
encountered
a
sand
layer
(3:48).
Explain
why
this
effect
happens
using
your
knowledge
of
soil
hydraulic
potentials
and
hydraulic
_xhra:\’ct‘
loan
Yexture
d
%01l
and
Cncovr\"“
conductivity.
in
the
son3
PoeeS
poove
“he
vhon
watey
(was
mDV\'Aj
—meah
the
non
p
Are
cond,
adweSive
omd
Cohesive
forees
held
the
water
k
‘
o
A
encble
surgls
W
der
ewrtuplly
Llows
-\"r\(wgy\
e
send
an
o
et
e
’n‘o’&:;r
-Y’ni
ool
Decomes
mont,
put
dhe
sand
does
not
allop
weter
»
.
*
pass
thiovgy
o
n
maC
porental
in
s
Soth
[y
o
O
wWoul
reso\r
in
lo
The
&
dnesion
ond
C
hesion
outd
¥
|
.
h'r:‘"flfi
(:5
e
\\;drav\vc
?\,1’«144;\\-
Gmo\\\of
Qores
and
o
lowor
Mdm"l"
e,flfl.\\"
winlL
oW
in
|
soll
allow
Weder
o
slay
there
unh)
i
becomes
vory
Stvated,
that
1+
storts
ooM
S0t
<
Tv
S
flnrova\n
the
sand
The
woker
flows
throvgh
dhe
sand
oKy
af
b
1224
i
h\ah
-
oker
moves
do
the
‘ower
\nadrwl\(_
fo*tm"‘a\
below.
;
Kol
hydradi
¢
potente
Nkely
+o
stay
in
lover
ydravdic
potenRals.
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1S
dye
Yo
weker
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c¢)
Similarly
describe
what
happened
when
water
was
moving
through
a
silt
loam
textured
soil
and
encountered
a
clay
layer
(6:36).
Explain
why
this
effect
happens
using
your
knowledge
of
soil
hydraulic
potentials
and
hydraulic
conductivity.
The
<\
loapn
4exdurd
<ol
ollows
waler
to
Glow
well.
weder
e
plastsed
by
Ave
cley
layer
abdor
the
soil
obove
s
ek
due
do
Small
clay
@of®S
dbility
to
dvar
wedor
\ato
Ahem.
oter
dranstercing
dvogn
e
sol
s
ey
slor
o
ot
tokes
dime
for
puoker
do
Flow
Lhnudn
the
smoll
potes,
The
itk
loam
deschntd
Sol
has
@
hgher
hydmudic
potential
Ahan
the
cley
li\j“/
thos
uoder
mores
iMo
Ihe
Clay
loyor
o5
it
o
o
loner
hydraddic
potentia\s.
e
adhesi
ard
tonesion
forles
are
B'N'D"jw
n
the
seoller
pores
£
X
daj
(aver
ond
drows
n
ard
fherefne,
woter
moves
iate
Ahe
clay
layer.
d)
Similarly
explain
what
happened
when
the
water
encountered
a
diagonal
band
of
sandy
soil
that
extended
to
the
soil
surface
(10:50).
Explain
why
this
effect
happens
using
your
knowledge
of
soil
hydraulic
potentials
and
hydraulic
conductivity.
Be
sure
to
explain
the
difference
in
effect
caused
by
this
sand
band
compared
to
the
one
in
part
“b”
NQ‘V{
&‘Coun*‘fcc}
e
d!'OSV\q\
P
immcdl'cf\dj
vhore
i
F
.Sul?ca
Info
‘\’N_bar\&
ond
flled
Fhe
pores.
Tre
QSR
Eolntkal
treked
by
Ao
wall
in
Hre
chanred
Cavsed
lavge
pores
i
Sebeded
Soil
o
carny
vister
easily,
This
send
ditkee
fore
At
Sand
in
@A
B
becowse
WS
©
savrared
ond
pact
V9"
s
non-satureted
-
This
sotvrobed
soil
gy
pressure
potertial
and
ndter
oves
throosh
large
ores
casily,
while
non-setueted
2ol
hos
malC
potental
ond
odViesion
and
cohesion
moinknined
Hhe
water
in
the
small
gores
oppe
the
Sand
layer.
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