RANCHAL
A.A. Shiwalkar®,
rajeev, akbarthwal,
-à-vis their spectral
:d soil samples were
to 1800 nm. White
o silt loam and silty
YR 6/4) and reddish
32 per cent. The soil
spectral reflectance
relation carried out
perature regime and
stic, udic and cryic.
m hyperthermic in
ter Himalayas. High
gid soil temperature
linal zones, having
nical characteristics
intisols, Inceptisols,
The locations of 10
/ Altitude
g- (m)
TN 832
6'E
4’N 1144
6’E
DN 1485
2! E
5'N 1498
IF
8 N 1958
32 E
0’ N 1980
1 E
N 2684
4E
0’N 3185
2r
JN 3105
9' E
]*N 2684
dE
Surface soil samples collected from each site were air-dried and
passed through 2 mm sieve. Soils were analysed for their
physical and chemical characteristics. The procedures used for
determination of various soil properties are described in table2.
Table 2. Soil analytical procedures
Soil Property Method Reference
Particle Size International Jackson,1956;
Distribution Pipette Method Knuze,1965
pH-H,0 pH measures at Jackson,1973;
1: 2.5 soil/water Page et al., 1982
suspension
Organic carbon Walkley-Black Nelson and
procedure Sommers, 1982;
Walkley and
Black, 1934
CEC of Non- Ammonium Jackson, 1967
calcareous soils Acetate pH 7.0
Free Iron Oxides | Sodium Citrate-
dithionite
'extraction
FeO and Fe,0; Colorimetric
: determination by
decomposition of
silicates with
hydrofluoric-
sulphuric acid
mixture
Holmgren, 1967
Begheijn, 1979
2.3 Soil reflectance measurement
Soil diffuse reflectance spectra were recorded for each soil (2-
mm air-dried soil sample) using a FieldSpecPro NIR-I
Spectroradiometer (Analytical Spectral Devices Inc, Boulder,
Colorado) at a wavelength from 0.35 to 1.8 um with a spectral
sampling interval of 1 nm. Measurements were taken outdoors
on cloud less days. The average of ten spectra (the
manufacturer's default value) was recorded for each sample to
minimize instrument noise. Before reading each sample, ten
white reference spectra were recorded using calibrated
spectralon (Labsphere, Sutton, NH) placed at the same distance
from the foreoptic as the soil sample.
3. RESULTS AND DISCUSSION
3.1 Soil Characterization
The dominant morphological, physical and chemical
characteristics of soils have been given in table 3 & 4. The
colour of the dry soil varies from very dark grayish brown
(10YR3/2) at Shelang to light yellowish brown (2.5Y6/4) at
Pithoragarh. The soils are moderately well to well drained. The
texture varies from loam to sandy loam and silt loam. The total
clay content in soil ranges between 5.8 and 23.6 per cent
whereas the silt varies between 20.0 and 68.9 per cent. The
soils are acidic in nature with soil pH ranging from 5.2 to 6.8.
The soils, in general, have low CEC but rich in organic carbon
content.
3.2 Soil characteristics vis-à-vis soil reflectance
Salient soil characteristics of each site as well as soil
reflectance characteristics between 350 and 1800 nm
wavelength region has been discussed in the following
IAPRS & SIS, Vol.34, Part 7, “Resource and Environmental Monitoring”, Hyderabad, India,2002
paragraphs. The soil reflectance spectra are grouped altitude-
wise viz. low altitude (<1500 m), mid altitude (1500-2500 m)
and high altitude (>2500 m) and has been discussed with
respect to their shape and absorption bands wherever noticed.
The spectral data between 1350-1450 nm were not reliable due
to atmospheric water absorption band, hence, not considered.
Table 3. Morphological characteristics of soils
Soil Colour Text Consis- Drainage
(Dry) ure tency
Karan Grayish 1 sh,fi,ss, ps | Well
Prayag brown drained
Baijnath Brown sl sh,fr,ss,ps Mod.well
drained
Mahergaon | Light 1 h,fi,s,ps Well
yellowish drained
brown
Pithoragarh | Olive sil h,fi,s,p Well
yellow drained
Pandukesh Dark sl sh,fr,so,po Mod. well
war grayish drained
brown
Chaukori Brown 1 sh,vfr,ss,ps | Well
drained
Auli Light sl S, Vfr,ss,ps Mod. well
olive drained
brown
Malari Reddish sl sh,fr,ss,po Well
yellow drained
Badrinath Brown sl sh,fi,ss,po Well
drained
Shelang Very dark | 1 S, Vfr,ss,ps Mod. well
grayish drained
brown
Table 4. Particle size distribution, pH and organic carbon
Soil Particle size pH | Org | CEC
distribution (96) 128 oF Ce cmol
Sand Silt | Clay (%) | (p+)
(2.0- (0.05- | («0.00 kg!
0.05 0.000 | 2mm)
mm) mm)
Karan 912 39.1 97-1793 12097 73
Prayag
Baijnath 72.5 21.7 581 53.7 | 1.04 3.8
Maher- 34.4 44.5 21.l 5.8 3.0 13.2
gaon
Pithorag 7.6 68.9 A Da 9.3
arh
Panduke 63.3 24.0 12.7 6.5 4-8. 76 22.5
shwar
Chaukori 39.6 37.2 233 |. 5.4 | 3.098 12.7
Auli 66.9 21.5 11.6 | 6.0 | 4.06 15.3
Malari 56.6 32.0 11.4: |--6-3-1-0.92 94
Badrinat 70.8 20.0 92 1; 61.4:3.69 14.0
h
Shelang 36,0 39.6 23.6,.1..5.2.1.-8,32. |... 1d.
n.d. — not determined
3.3 Soils of low altitudes
Karan Prayag soils: Soils are moderately deep, grayish brown
(2.5Y 5/2 D) and dark grayish brown (2.5Y4/2 M), sandy loam
at surface, well drained, moderately acid (pH 5.7) occurring on
hill slopes. Based on Keys to Soil Taxonomy (Soil Survey Staff
