Agriculture Reference
In-Depth Information
district which is considered as one of the main tea growing districts in the country.
Hence, research was conducted with following objectives:
• Application of remote sensing to infer the potential productivity of tea at synop-
tic and micro level landscapes.
• Potential of using remote sensing as tool for yield prediction and early warning
system tea plantations.
• Application of hydrogeomorphology base to study the potential yields of tea
plantations.
1.1 Study Area
Sri Lanka lies in the Indian ocean between longitudes 79° 39 and 81° 53′ East and
latitudes 5° 54 and 9° 52′ North. It covers a total of 65,609.8 Km
2
area. Geologi-
cally, Sri Lanka is located in the South-Asian Tectonic plate and 90 % of country
has underlying Precambrian crystalline rocks (Ganashan
1996
). The metamorphic
basement has been subdivided into three major units, namely the Vijayan Complex
in the east, the Highland Complex in the central and the Wanni Complex in the west.
Ratnapura, which is the area of interest for this study, is covered by Highland Com-
plex, and is composed of pelitic, mafic and quartzo-feldspathic granulites, abundant
charnockitic rocks (Kehelpannala
1997
).
Climate condition of the country is basically determined by the geographical
location. The mean temperature is 27.5 °C over low lands. However, in higher el-
evation mountain regions, the mean monthly temperatures vary from 13 to 16 °C.
Most parts of the country experience only a small variation in mean monthly tem-
peratures throughout the year. The relative humidity varies generally from about
70 % during the day to about 90-95 % at night.
The two monsoonal periods, the southwest (May-September) and the northeast
(December -February) are responsible for major part of the annual precipitation.
South western quarter and the central highlands of the country get mostly south-
west monsoon rain while north east monsoon produces rain throughout the island.
Based on the mean annual rainfall, the country is classified into three major climatic
zones: Dry zone (1,250-1,525 mm), Intermediate zone (1,525-2,280 mm) and wet
zone (2,280-5,100 mm) (Ganashan
1996
).
In the dry zone, the major soil group is the well-drained reddish brown earths.
The wet zone is characterized by predominant red yellow podzolic soils with bog,
half bog soils, and sandy regosols along the southwest coast. The intermediate zone
displays a transition from reddish brown earths to red yellow podsolic soils, with
non-calcic brown loam in patches (Panabokke
1996
).
Agriculture sector can be divided into two main categories, plantation agricul-
ture and non-plantation sector. About 1.8 million farm families are engaged in non-
plantation sector which are characterized by small-scale rice-based farming under
rainfed and artificial irrigation. However, plantations involve with largescale culti-
vation of perennial crops such as tea, rubber, coconut, etc.
