• Assessment of soil quality status through estimation of physico-chemical parameters across different land use types in Uttar Kannada district, Central Western Ghats through field sample collection.
• Mapping soil quality across the different land uses of Uttar Kannada district, Central Western Ghats.

Study Area

The Western Ghats or Sahyadri are the main hill range in peninsular India that run along the states of Maharashtra, Goa, Karnataka, Kerala and Tamil Nadu starting from the river Tapti in the north to Kanyakumari in the south, extending over a length of 1300 km is one of the 18 biodiversity hot spots (Myers, 1990, Gadgil, 1996) of the world.
Uttara Kannada, one of the 29 districts in Karnataka, India (Figure 2), is a hilly forested terrain situated in the central region of the Western Ghats in South India (Bhat, 2002). It is northernmost of the three coastal districts of the state stretching alongside the Arabian Sea. The Western Ghats divide the district into two parts, five of its talukes are in coastal plains and six of them are above the Ghats. Most of the district is covered with the hill ranges of the Western Ghats, one among the 25 biodiversity hot spots of the world (Myers et al., 2000). Over 4,000 species of flowering plants (38% endemics), 330 butterflies (11% endemics), 289 fishes (41% endemics), 135 amphibians (75% endemics), 156 reptiles (62 endemics), 508 birds (4% endemics) and 120 mammals (12 % endemics) are found in the Western Ghats (Sreekanta et al, 2007). Various types of ecosystems flourish in the soils of this district. It is one of the biggest districts in Karnataka. Uttara Kannada has great diversity in its landscape, soil and rainfall. It is the richest forest district of Karnataka endowed with a diverse variety of flora and fauna.

The district is located in the mid-western part of the state. It lies between 74°09' to 75°10' east longitude and 13°55' to 15°03' north latitude. Total area is 10,291 sq km which is 5.37% of the total area of the state. It extends to about 328 km north south and about 100 km east west. Most of the district is hilly and thickly wooded. The coast stretches in a long nearly straight line to the south east except the shallow Karwar and Belekeri bays .The population of the district was 1,353,644 according to 2001 census, a 10.90% increase since 1991 census. For administrative purpose the district has been divided into 11 talukes namely Ankola, Bhatkal, Haliyal, Honnavar, Karwar, Kumta, Mundgod, Siddapur Sirsi, Joida and Yellapur. The town of Karwar is the administrative headquarters of the district.

The district is hilly and wooded in most parts. The district has three main regions: The coastlands, the Sahayadrian interior and the eastern margin that merges with the Deccan plains. The coastal lands are best developed areas with a high degree of economic development and a high density of population. The Sahayadrian region is mostly forested and only the roads crossing the Ghats sustain some human life (Kamath, 1985). The eastern margin is an undulating land, partly under forest and partly cleared up for agriculture.

GEOLOGICAL SETTING OF THE REGION
The district consists of rock formation of Archaen complex, the oldest of the earth’s crust (Bourgeon, 1989). The district is traversed by a system of ridges of the Western Ghats and a plateau on the west descending rapidly to a rather narrow strip of lowland covered by alluvium. Gneisses are frequently overlaid by a capping of laterite which is locally the source of Iron and Manganese ores. Eastern part of the district consists of a varied assemblage of Granite and Schist. In Dharwar district adjoining Uttara Kannada, chlorite-schist is dominant. The other rock formations belonging to this district are Quartzite, Magnetic- Quartzite, Limonite Quartzite, Lime-stones and other basic igneous rocks.

 

South-west monsoon winds contribute an average rainfall of 2,835.5mm.to the district. Coastal zone receives an average of 3500 mm of annual rainfall.  Heavy rain occurs during the three months from June to August and later decreases rapidly towards October-November. July is the rainiest month. In the district nearly 80% of the land is under the control of the forest department. According to the Landsat imagery out of the 10, 291 sq km of the total geographical area of the district 67.04% is under forest, 1.94 under paddy and millet cultivation, 1.26 under coconut and areca garden, 1.94% under rocky and the remaining 27.8 is under habitation and reservoirs (Ramachandra et al, 1999). The tropical evergreen forest, the planet’s most productive, diverse, and the oldest ecosystem still persists in their primeval glory on the Ghats of Uttara Kannada (Chandran, 1984). The main types of forest found in this district belong to evergreen, semi-evergreen, moist deciduous and dry deciduous types. Forests on degradation produce scrub, savanna and grasslands (Arora, 1961; Pascal et al French Inst maps). The evergreen forests are found in places where rainfall is more than 225 cm. The different forest types are having a relationship with the amount of rainfall. The summer is pretty hot and winter is cool. The minimum temperature is 18°C and maximum is 38 °C.