Characterization and Classification of Red Soils from Tamil Nadu

Four typical pedons representing agriculture, forage and tree crops land uses were studied in red soil region (Kutturavupatti village of Sivagangai district) of Tamil Nadu during 2005-06. Soils were characterized for important morphological, physical and chemical characteristics to define limitations for vegetation establishment at village level. Based on soil characteristics four soil series viz., Sivagangai (P₁), Melapoongudi (P₂), Tamarakki (P₃) and Keelapoongudi (P₄) were identified and named. All the soils were found deep in depth and have subangular blocky structure in surface and sub surface. The soils texture varied from loamy sand to clay. Among the pedons, more than 70% gravels were recoreded in pedon 1, whereas more than 10 % free CaCO₃ and high pH of 8.3 was found in pedon 3. The bulk density, available soil moisture, organic carbon and cation exchange capacity ranged from 1.11 to 1.33 Mgm^-3, 4.2 to 16.2%, 0.11 to 0.60% and 8.79 to 41.47 c mol (p⁺) kg^-1, respectively. The order of dominance of exchangeable bases was Ca²⁺>Mg²⁺>Na⁺>K⁺. The soils were classified into alfisol (pedon 1 and 4) and Inceptisol (pedon 2 and 3) as per USDA system of classification.