Abstract:
With the agricultural development in the Northern region of Sri Lanka, there is a need to characterize the soils for land
use planning and environmental applications. The objective of this study was to characterize the soils in the
Northern region of Sri Lanka to extend the soil data base of the Dry zone, specially the Calcic Red Latasols and Calcic
Yellow Latasols, the two major soils occurring in the Jaffna district. These soils were identified, benchmark sites were
selected and the landscape features were recorded with soil profile descriptions. Soil physical and chemical
properties were studied in each horizon of the soil profile using standard procedures. The excessively drained Calcic
Red Latasols occur in all areas other than then depressions of the Karst plains while the Calcic Yellow Latasols which
are imperfectly drained occur in depressions of the land unit. The results reveled that Calcic Red latasols show a sandy
loam texture while the Calcic Yellow latasols are slightly heavier showing a sandy clay loam texture. The soil
eordibility factor of the Calcic Red Latasols and Calcic Yellow Latasols were 0.21 (medium risk) and 0.31 (high risk),
respectively. Soil conservation measures to reduce erosion by water are needed for the latter. Both the soils show
susceptibility to wind erosion and conservation practices such as mulching is recommended to overcome this
problem during the dry periods. The saturated hydraulic conductivity of Calcic Red Latasols was very rapid showing
the danger of leaching of inputs as fertilizers and pesticides to ground water easily.
