DOI: 10.36347/sajb.2013.v01i05.010

Pages: 200-208

The present study was an attempt to know the fertility status of soils in five selected regions (H.D.Kote, Madikeri, Sakaleshpur, Shimoga and Sirsi) of the Western Ghats of Karnataka with Mysore region as control for comparison for the purpose of exploration of wild (tree type) castor, Ricinus communis L., a primary host plant of the domesticated vanya silkworm, Samia cynthia ricini Boisduval. The selection of regions for drawing soil samples were based on the extent of area (Western Ghats) covered in Karnataka giving due weightage for the entire region. The soil samples were drawn at a depth of 0-45 cm from five spots of each region for collection of 250 g of composite samples adopting quadrant technique to study the chemical properties (pH, electrical conductivity, organic carbon, available nitrogen, phosphorus and potassium) of soils. The chemical properties of soils were statistically varied among the selected regions of the Western Ghats of Karnataka at 5% level of probability. pH and EC of soils varied between 5.25 (Sirsi) and 7.83 (Madikeri), 0.03 (Sirsi) and 0.28 (Shimoga) m.mhos/cm, respectively. Organic carbon and available nitrogen contents were significantly more (1.59% and 709.2 kg/ha) with H.D. Kote region and Sakaleshpur region recorded less contents (0.47% and 250.6 kg/ha). The soils of Madikeri region had higher available phosphorus content (34.34 kg/ha) and it was lower with Sirsi region (9.450 kg/ha). Both Madikeri and Sakaleshpur regions recorded highest potassium content of 717.0 kg/ha with least being in Sirsi region (90.00 kg/ha). The correlation co-efficients worked out for chemical properties of soils established non-significant relationship among them, except for organic carbon content, wherein it showed significant (P≤0.01) positive relationship with available nitrogen content of soils.