Rangeland reflectance characteristics measured by aircraft and spacecraft sensors


Deering, D.W.

Dissertation Abstracts International, B 39(7): 3081-3082

1979


Rangeland vegetation and soil measurements were related to composite rangeland reflectance measurements from Landsat multispectral scanners (MSS) and color infrared aerial photographs. Ground data and remote sensor measurements were acquired on six sample dates in three growing seasons from a rangeland study site in north central Texas. The potential for using a normalized infrared/red difference parameter for measuring rangeland vegetation or for monitoring vegetation conditions from satellite or aircraft was indicated. In assessing the relationships between scene components and composite scene reflectance, a sun angle related shadow influence, which generally has been ignored, was identified as being important. Results of this study also strongly suggest that quantitative assessment of vegetation conditions by remote sensing must account for weather related influences on reflectance.

AGRICULTURE,
RANGE
MANAGEMENT
3081-B
increased
rates
of
applied
potassium.
In
1977,
after
three
years
of
alfalfa
cultivation,
exchangeable
potassium
had
only
been
reduced
38%
of
the
initial
levels
in
the
plots
receiving
no
potassium
fertilizer.
The
alfalfa
crop
removed
sufficient
quantities
of
potassium
to
completely
deplete
the
exchangeable
potassium
in
one
year;
however,
soil
levels
of
exchangeable
potassium
did
not
reflect
this
depletion.
Analysis
of
the
sup-
plying
power
of
the
soil
in
August,
1977,
following
three
years
of
alfalfa
cultivation,
indicated
that
the
soil
receiving
no
potas-
sium
fertilizer
contained
levels
of
potassium
which
would
be
insufficient
for
continued
optimum
growth
of
alfalfa.
The
soil
potassium
supplying
power
was
large
enough
to
maintain
an
alfalfa
crop
producing
approximately
7870
kg
dry
matter/ha.
Increased
rates
of
applied
potassium
had
no
effect
on
canopy
development
in
1976
and
1977.
Potassium
accumulation
was
increased
with
increased
rates
of
applied
potassium,
but
leaf
and
stem
potassium
decreased
after
14
days
of
regrowth.
Po-
tassium
was
apparently
taken
up
during
the
first
two
weeks
of
regrowth
and
redistributed
during
the
remainder
of
the
re-
growth
period.
Photosynthesis,
dark
respiration,
photorespira-
tion,
chlorophyll
content
and
ribulose
1,5-biphosphate
car-
boxylase
activity
were
not
affected
by
increased
rates
of
applied
potassium.
In
the
greenhouse,
photosynthesis,
photorespiration
and
leaf
potassium
were
significantly
reduced
by
a
mild
and
severe
potassium
deficiency.
Dark
respiration
was
significantly
in-
creased
by
severe
potassium
deficiency.
Leaf
resistance
to
carbon
dioxide
diffusion
was
significantly
increased
by
severe
potassium
deficiency
and
mesophyll
resistance
to
carbon
diox-
ide
diffusion
was
significantly
increased
by
both
mild
and
se-
vere
deficiency.
Photosystem
I
and
II
activity
and
chlorophyll
content
were
not
affected
by
mild
or
severe
potassium
de-
ficiency.
Ribulose
1,5-biphosphate
carboxylase
apparent
ac-
tivity
was
significantly
decreased
by
severe
potassium
de-
ficiency.
The
increased
mesophyll
resistance
was
due
to
a
decrease
in
carbon
dioxide
fixation
by
ribulose
1,5-biphos-
phate
carboxylase.
In
the
laboratory,
it
was
determined
that
ribulose
1,5-
biphosphate
carboxylase
synthesis
and
not
activity
was
re-
duced
in
potassium
deficient
leaves.
Incorporation
of
'
4
C-
leucine
was
stimulated
by
potassium
in
potassium
deficient
leaves.
Potassium
stimulated
carboxylase
synthesis
was
suppressed
by
actinomycin
D
and
cycloheximide,
indicating
that
it
involved
DNA
dependent
RNA
synthesis
and
subsequent
protein
synthesis.
Light
was
shown
to
be
required
for
synthe-
sis.
Decreased
synthesis
of
ribulose
1,5-biphosphate
carboxyl-
ase
should
result
in
a
decrease
in
photosynthesis
and
photo-
respiration
as
was
observed.
PROTEOLYTIC
ENZYME
ACTIVITIES
IN
CORN
(ZEA
MAYS
L.)
LEAVES
DURING
WATER
DEFICIT
AND
SENESCENCE
Order
No.
7821052
SOONG,
Tai-Sen
Thomas,
Ph.D.
University
of
Illinois
at
Urbana—Champaign,
1978.
91pp.
The
relationship
between
proteolytic
hydrolysis
of
leaf
pro-
tein
and
the
accumulation
of
N
by
corn
kernels
was
investi-
gated
under
field
conditions
in
1975-1976.
The
6
inbreds
and
8
hybrids
tested
included
current
commercial
inbreds
and
Illinois
high
and
low
protein
selections.
Endopeptidase
activi-
ties
(pH
5.4
and
7.5
with
casein)
were
measured
in
the
mid-
segment
of
the
ear
leaf
at
biweekly
intervals
from
pollination
to
maturity.
Accumulation
of
stover
and
stover
N
prior
to
grain
development
and
yields
of
grain,
grain
N,
stover
and
stover
N
at
maturity
were
measured.
The
grain
N
was
transferred
mainly
from
the
vegetation,
as
the
loss
of
N
from
the
vegetation
during
kernel
development
was
significantly
correlated
with
the
total
amount
of
grain
N
yield.
Endopeptidases
(pH
7.5
and
5.4)
were
significantly
cor-
related
(r
=
+.61
in
1975
and
r
=
+.79
in
1976)
with
percent
grain
N
at
maturity.
A
positive
correlation
(r
=
+.60)
between
endopeptidase
(pH
7.5)
and
total
grain
N
was
only
observed
for
the
hybrids
or
vegetatively
vigorous
inbreds.
In
another
study,
the
changes
of
exo-
and
endopeptidase
ac-
tivities,
protein,
amino
acids
and
chlorophyll
in
detached
leaves
incubated
for
48
hr
in
a
dark,
humid
30
C
environment
were
compared
with
comparable
samples
assayed
at
time
of
harvest.
When
senescing
leaves
(harvested
from
corn
plants
in
the
vege-
tative
stage)
were
incubated
in
the
dark,
protein
and
chloro-
phyll
contents
decreased,
amino
acids
accumulated
amino-
and
carboxypeptidase
activities
remained
high
and
unchanged
and
endopeptidase
activities
were
low
and
did
not
change.
When
senescing
leaves
(harvested
from
corn
plants
during
grain
fill)
were
incubated
in
the
dark,
protein
and
chlorophyll
contents
decreased,
amino
acids
increased,
and
endopeptidase
activities
increased
markedly,
especially
at
pH
7.5.
These
data
show
that
proteolytic
enzymes
in
detached
and
darkened
senescing
leaves
are
different
(in
amounts
and
kinds)
from
the
proteolytic
enzymes
in
naturally
senescing
leaves.
Thus
artificial
(dark)
senescence
cannot
be
used
as
a
technique
for
screening
of
corn
seedlings
for
their
genetic
potential
to
produce
endopeptidases.
Proteolytic
enzymes
in
water
deficit
induced
senescing
leaves
were
also
studied.
In
well-watered
control
plants,
only
minor
changes
were
observed.
When
water
was
withheld,
the
loss
(rate
and
sequence)
of
protein,
amino-
and
carboxypep-
tidase
activities
from
leaf
2,
3,
and
4
(from
bottom)
was
re-
lated
to
the
loss
of
water
from
the
tissue.
In
contrast,
endo-
peptidase
activities
(pH
5.4
and
7.5
with
casein)
increased
during
the
initial
phase
of
water
deficit
and
then
decreased
when
two-thirds
of
leaf
protein
was
lost.
A
pigment
with
an
absorption
maximum
of
495,
m
increased
in
all
water-deficit
leaves.
Because
the
assay
for
this
pigment
is
rapid
and
sim-
ple,
its
usefulness
as
a
corollary
measurement
in
drought
studies
of
corn
is
suggested.
A
technique
was
developed
to
study
the
sequential
changes
of
ribonuclease
and
protease
ac-
tivities
under
controlled
moderate
water
deficit
(plants
were
rapidly
desiccated
for
1
h
prior
to
transfer
to
a
humid
cham-
ber).
The
endopeptidase
activities
(pH
5.4,
with
casein
and
pH
3.8,
with
hemoglobin)
increased
after
9
hr
incubation
in
a
humid
chamber
and
ribonuclease
activities
are
initiated
by
water
deficit
and
these
increases
are
associated
with
an
ob-
served
protein
loss
in
water
deficit
leaves.
AGRICULTURE,
RANGE
MANAGEMENT
RANGELAND
REFLECTANCE
CHARACTERISTICS
MEA—
SURED
BY
AIRCRAFT
AND
SPACECRAFT
SENSORS
Order
No.
7900962
DEERING,
Donald
Wayne,
Ph.D.
Texas
A&M
University,
1978.
338pp.
Chairman:
Dr.
Robert
H.
Haas
Rangeland
vegetation
and
soil
measurements
were
related
to
composite
rangeland
reflectance
measurements
from
Land-
sat
multispectral
scanners
(MSS)
and
color
infrared
aerial
photographs.
Ground
data
and
remote
sensor
measurements
were
acquired
on
six
sample
dates
in
three
growing
seasons
from
a
rangeland
study
site
in
north
central
Texas.
The
po-
tential
for
using
a
normalized
infrared/red
difference
param-
eter
for
measuring
rangeland
vegetation
or
for
monitoring
vegetation
conditions
from
satellite
or
aircraft
was
indicated.
In
assessing
the
relationships
between
scene
components
and
composite
scene
reflectance,
a
sun
angle
related
shadow
influ-
ence,
which
generally
has
been
ignored,
was
identified
as
being
important.
Results
of
this
study
also
strongly
suggest
that
quantitative
assessment
of
vegetation
conditions
by
remote
sensing
must
account
for
weather
related
influences
on
re-
flectance.
Individual
Landsat
MSS
band
values
were
strongly
affected
3082-B
AGRONOMY
by
factors
influencing
scene
brightness,
including
the
amount
of
shadow
in
the
scene.
A
normalized
red/infrared
difference
parameter,
ND6
((Band
6
Band
5)
÷
(Band
6
+
5)),
was
effec-
tive
in
adjusting
for
much
of
the
variation
in
scene
brightness.
The
ND6
parameter
was
more
sensitive
to
variations
in
the
functioning
green
biomass
components
of
the
scene
than
were
individual
spectral
bands
or
the
other
vegetation
indices
eval-
uated.
All
of
the
vegetation
indices
that
employed
Band
6
were
more
closely
related
to
the
green
plant
component
of
the
scene
than
those
using
Band
7.
Shadow
effects
had
a
greater
influence
on
reflectance
mea-
surements
taken
from
color
infrared
aerial
photography
than
from
Landsat.
For
three
scales
of
photography,
measured
re-
flectance
differences
were
shown
to
be
due
to
differences
in
sun
angle
at
the
times
of
photography.
A
normalized
infrared/
red
difference
parameter,
IR-R
((infrared
reflectance
red
reflectance)
÷
overall
film
exposure-derived
reflectance),
ad-
justed
for
some
of
the
shadow
effects
and
effectively
adjusted
for
most
of
the
film
exposure
and
processing
differences
be-
tween
dates.
The
IR-R
parameter
response
was
almost
iden-
tical
to
that
of
the
Landsat
ND6
parameter.
The
relationships
between
reflectance
and
biomass
or
re-
flectance
and
plant
moisture
content
(kg/ha)
were
better
for
moderately
high
sun
elevations
(i.e.,
greater
than
approxi-
mately
55
°
)
than
for
lower
sun
angles.
Therefore,
remote
sensor
data
to
be
used
in
quantitative
assessment
of
rangeland
vegetation
conditions,
or
used
in
multistage
comparisons,
must
be
acquired
at
moderately
high
sun
elevations.
Multiple
regression
models,
involving
five
ground
variables,
were
evaluated
to
test
the
hypothesis
that
rangeland
scene
re-
flectance
is
a
function
of
vegetation
and
soil
components
of
the
scene.
More
than
80%
of
the
ND6
or
IR-R
variation
could
be
accounted
for
by
the
five
ground
variables
used.
Plant
mois-
ture
content
(kg/ha),
green
plant
cover,
and
soil
moisture
had
the
greatest
influence
on
scene
reflectance.
It
was
shown
that
a
prediction
model
for
monitoring
the
vegetation
on
both
the
Deep
Upland
and
Rolling
Hill
range
sites
would
have
to
be
a
curvilinear
model.
The
influences
of
the
various
scene
components
on
reflec-
tance
were
found
to
vary
with
growing
conditions.
Three
weather
variables
were
associated
with
changes
in
temporal
reflectance
differences
and
were
successfully
used
in
a
re-
flectance
model
to
adjust
for
growing
condition
differences.
The
selected
weather
variables
included:
1)
total
precipitation
during
the
9
days
preceding
Landsat
overpass,
2)
minimum
air
temperature
on
the
day
of
the
overpass,
and
3)
average
maximum
air
temperature
during
the
3
days
preceding
the
overpass.
When
green
biomass
data
were
adjusted
for
weather
influences
on
reflectance,
the
model
accounted
for
approxi-
mately
90%
of
the
ND6
and
IR-R
variations.
Results
of
the
study
provide
guidelines
for
acquiring
re-
mote
sensor
data
to
be
used
in
quantitative
vegetation
surveys.
The
results
are
particularly
important
for
applications
involv-
ing
automated
data
interpretation.
AGRONOMY
THE
INFLUENCE
OF
GRAZING
INTENSITY
ON
THE
PER—
FORMANCE
OF
TROPICAL
GRASSES
Order
No.
7900029
ADJEI,
Martin
Bani,
Ph.D.
The
University
of
Florida,
1978.
184pp.
Chairman:
Coleman
Y.
Ward
Grazing
trials
were
conducted
at
the
University
of
Florida
Agricultural
Research
Center,
Ona,
Florida,
in
1976
and
1977
to
study
the
effects
of
three
stocking
rates
(SR)
(7.5,
low;
10,
medium;
and
15,
high;
cattle/ha)
and
the
associated
grazing
pressures
on
yield,
quality,
forage
utilization,
stubble
carbo-
hydrate
reserves
and
cattle
performance
of
three
African
star-
grasses;
namely,
'UF-5'
and
'McCaleb'
(Cynodon
aethiopicus
Clayton
and
Harland)
and
‘UF-4'
(Cynodon
nlemfuensis
Van-
deryst).
Additionally,
the
medium
stocking
rate
was
imposed
on
`Transvala'
digitgrass
(Digitaria
decumbens
Stent.)
and
'Pensacola'
bahiagrass
(Paspalum
notatum
flugge).
All
pastures
received
one
uniform
application
of
0-44-88
kg/ha
(N-P205-K20)
and
a
total
of
220
kg/ha
N
in
three
split
applications,
annually.
The
two-year
seasonal
forage
production
averaged
over
all
stargrasses
were
17.0
metric
tons/ha
at
the
low,
18.3
at
the
medium,
and
20.1
at
the
high
SR.
The
lower
yield
with
decreas-
ing
SR
was
attributed
to
the
existence
of
a
greater
metabolic
sink
in
the
standing
residue
under
lenient
grazing
pressure.
Net
dry
matter
production
was
estimated
at
15
and
10
metric
tons/ha
on
digitgrass
and
bahiagrass,
respectively,
at
the
me-
dium
SR.
In
vitro
organic
matter
digestion
(IVOMD)
of
stargrass
for--
age
on
offer
ranged
between
44
and
54%,
exhibiting
a
positive
linear
response
to
increasing
SR.
The
IVOMD
of
digitgrass
(51%)
was
very
similar
to
that
of
OF-5
stargrass
but
superior
to
OF-4,
and
McCaleb
stargrasses
and
bahiagrass.
There
was
no
difference
in
crude
protein
content
among
the
five
entries
of
tropical
grasses
which
averaged
9.9%.
Utilization
of
seasonal
dry
matter
yield
by
cattle
varied
from
75
to
95%
and
was
directly
related
to
SR.
However,
in-
take
at
the
high
SR
(7.6
kg
DM/cattle/day)
was
lower
than
those
at
the
lenient
grazing
pressures
(9.3
and
10.2
at
the
medium
and
low
SR,
respectively).
Forage
dry
matter
consumed
an-
nually
at
the
medium
SR
averaged
16.7
metric
tons/ha
for
the
stargrasses
as
compared
with
14.9
on
digitgrass
and
9.9
on
bahiagrass.
Total
nonstructural
carbohydrate
(TNC)
reserves
in
grass
stubble
and
roots
exhibited
a
marked
quadratic
response
to
grazing.
A
regrowth
(rest
period)
of
28
days
was
sufficient
to
replenish
the
depleted
TNC
on
all
treatments
except
digit-
grass
in
the
fall
season.
The
concentration
of
TNC
reserves
was
much
higher
in
the
roots
than
in
the
stubble
of
stargrass.
However,
TNC
was
greater
in
the
stubble
than
in
the
roots
of
digitgrass,
and
higher
in
the
rhizomes
than
roots
of
bahiagrass.
The
minimum
TNC
levels
in
both
the
roots
(6.8
to
7.5%
on
DM
basis)
and
the
stubble
(4
to
5%)
of
stargrasses
were
observed
at
the
high
SR.
Bahiagrass
rhizomes
contained
the
highest
level
of
TNC
(23%).
Cattle
average
daily
gains
(ADG)
from
0.18
to
0.56
kg/day
on
stargrasses
were
an
inverse
linear
function
of
stocking
rate,
a
linear
function
of
available
forage
or
residue
(metric
tons/ha)
and
a
nonlinear
function
of
grazing
pressure
(kg
DM/100
kg
BW/day).
The
minimum
grazing
pressure
required
to
obtain
maximum
ADG
on
stargrass
ranged
from
6
to
7
kg
available
DM/100
kg
BW/day
or
the
accumulation
of
2
to
4
kg
residue/
100
kg
BW/day
based
on
varietal
differences.
Beef
gains
per
hectare
averaged
over
2
years
on
stargrass
were
470
kg/ha
at
the
high
SR,
617
at
the
medium,
and
576
at
the
low.
Although
there
was
no
statistical
difference
in
ADG
on
star-
grass
(0.35
kg/day)
compared
with
digitgrass
(0.28
kg/day)
or
bahiagrass
(0.22
kg/day),
these
rates
of
gain
created
signifi-
cant
differences
in
total
beef
gain/ha
in
1976,
which
varied
from
580
kg/ha
on
stargrass,
461
on
digitgrass
to
369
on
bahia-
grass,
all
measured
at
the
medium
SR.
EVALUATION
OF
CULTIVARS
AND
CULTURAL
PRAC—
TICES
OF
SEVERAL
CROPS
FOR
TROPICAL
MUL—
TIPLE
CROPPING
Order
No.
7900030
AKHANDA,
Md.
Abdul
Muttalib,
Ph.D.
The
University
of
Flor-
ida,
1978.
176pp.
Chairman:
Victor
E.
Green,
Jr.
Appropriate
crop
cultivars,
row
widths,
plant
populations
and
time
of
planting
are
essential
aspects
in
developing
suc-
cessful
multiple
cropping
systems.
Investigations
were