Methods
To evaluate the soil quality, a network of soil quality monitoring sites
(SQMS) were established following the agro-climatic variability along
the natural forest and traditional coffee growing areas in the Western
Ghats. A total of 60 SQMS were excavated of which 46 sites were located
in coffee plantations and 14 in forests adjacent to coffee plantations.
In Chikmagalur a total of 9 profiles from coffee ecosystem and 4
profiles from natural forest ecosystem were studied. In Wayanad, 8
profiles under coffee plantation and 4 profiles from natural forest
ecosystem, and in Idukki, 3 profiles each from coffee plantation and
natural forest ecosystem were studied to understand the effects of
conversion. From these identified study sites, six typifying pedons
representing the area, three from natural forest ecosystem and three
from coffee plantation ecosystem from the adjoining areas located in the
Eastern (Malanad) hills, Nilgiri hills and Kumili hills of Western Ghats
respectively, are described and characterized to meet the objectives of
the study.
The details of the profiles for which analyses were carried out include:
Pedon 1 and 2 are located in the Chikmagalur district of Eastern hills
of Western Ghats in which pedon 1 (Chikmagalur- Forest) was selected
from a natural forest in Chikmagalur district of Karnataka adjacent to
the CCRI campus. This steep sloping area (15-25 per cent) with slope
length 300-600 m is located at an elevation of 805 m above MSL within
latitude 13º 21’ 35.1″ N and longitude 75º 25’ 28.0″ E. Pedon 2
(Chikmagalur- Coffee ) was excavated from the CCRI coffee plantation
located at the Balehonnur panchayat, Koppa taluk of Chikmagalur
district. The coffee plantation is located within latitude 13º 21’ 40.0″
N and longitude 75º 25’ 38.5″ E at an elevation of 827 m above MSL with
a slope of 5-10 per cent with 150-300 m slope length. The geology is
granite with weathered granite as the soil parent material.
Pedon 3 and Pedon 4 represents the Nilgiri hills of western Ghats where
Pedon 3: (Wayanad- Forest) was excavated from an evergreen forest
situated within latitude 11º 46’ 17.5″ N and longitude 76º 07’ 43.2″ E
in the Panamaram panchayat of Wayanad district of Kerala. The
physiography is gently sloping highlands with 3-5 per cent slope and
150-300 m slope length. The geology is Archean granite gneiss and soil
parent material is weathered granite gneiss. Pedon 4 (Wayanad- Coffee)
belongs to the coffee plantation in the Vattakkara estate of Meenanagadi
panchayat, S. Battery taluk in the Wayanad district of Kerala and it
lies within latitude 11º 41’ 54.9″ N and longitude 76º 11’ 33.6″ E. The
site has a slope of 5-10 per cent with 150-300 m length. The geology is
granite and soil parent material is weathered granite.
Pedon 5 and 6 were excavated from the Kumili hills of Western Ghats in
the Idukki district. Pedon 5: (Idukki Forest) is dug from a forest
ecosystem belonging to the Udumbanchola Taluk of Shantanpara Panchayat
in Idukki district of Kerala. The pedon lies within a latitude of 09º
56’ 13.1″ N and longitude 77º 13’ 43.2″ E. The area has a slope of 5-10
per cent and slope length of 150-300 m. Pedon 6: (Idukki- Coffee) is
from Gudanpara MNJ estate in the Shanthanpara panchayat of Idukki
district of Kerala. The pedon lies within a latitude of 09º 56’ 42.5″ N
and longitude 77º 13’ 11.3″ E. The area has a slope of 3-5 per cent and
slope length of 300-600 m. The geology is granite gneiss and formed the
soil parent material after weathering.
Horizon-wise soil samples were analyzed using standard procedures for
soil morphological, physical and chemical parameters. Soil bulk density
was determined by the core method and mechanical composition of soils
was determined following the International Pipette method. Cation
exchange capacity (CEC) was determined by the ammonium acetate method
(Jackson,1958) . The ammonium acetate extract obtained from CEC
estimation was used to determine the exchangeable bases by atomic
absorption spectro-photometry and other soil chemical parameters were
determined using standard analytical techniques (Jackson,1958).
Soil organic carbon was determined following dry combustion method using
CHNS analyzer. Soil organic carbon stock for a given soil layer was
calculated by multiplying the organic carbon concentration in soil fine
earth with bulk density and soil depth using the following equation
(Grossman, 2001).
SOC= (C/100) X ρ X D X (1- frag.) x 100
where: SOC = soil organic carbon stock (kg m-2); C =
soil organic carbon concentration of soil fines (fraction < 2
mm) determined in the laboratory (%, g kg-1); ρ =
soil bulk density (g cm-3); D = depth of the sampled
soil layer (cm) and frag. = % volume of coarse fragments/100.