Characterization and Classification of Soils from Three Agro-climatic Zones of Belgavi District, Karnataka

摘要

Belgavi district in Karnataka is characterized by three contrasting agro-climatic zones viz., a relatively dry semi-arid northern dry zone (Zone-3) with low rainfall, a somewhat higher rainfall area termed transitional zone (Zone-8) nestling between the Western Ghats and Eastern Plains, and a heavy rainfall area comprising part of Western Ghats called hilly zone (Zone-9). This situation provided an opportunity to compare the properties of pedons occurring in these agro-climatic zones. Nine pedons, three each from the three micro-watersheds viz., Yadawad (Zone-3), Hukkeri (Zone-8) and Khanapur (Zone-9) were characterized for their morphological, physical and chemical properties with an objective of comparing their properties which have an implicationon their use and behaviour. Pedons from Yadawad micro-watershed (Zone-3) were deep, alkaline, calcareous and contained considerable amount of salts and are rich in clay content. The pedons of Hukkeri micro-watershed (Zone-8) were shallow to moderately deep, neutral, non-calcareous and contained low amount of salts and are somewhat coarse textured. Despite similar parent rock (basalt) in these two micro-watersheds, the variation in depth and texture are a direct result of erosion and deposition due to topographic variations. The pedons from Khanapur micro-watershed (Zone-9) were acidic, highly leached, and moderately fine textured. The variation in the soil properties of soils of Khanapur watershed sharply contrasted with soils of both Yadawad and Hukkeri watersheds due to high rainfall at the former compared to the latter. The soils of Yadawad micro-watershed classify as Typic Calciusterts, those of Hukkeri micro-watershed as Lithic and Typic Ustorthents and the soils of Khanapur micro-watershed as Oxic Dystrustepts and Kanhaplic Haplustalfs reflecting the leaching regime and erosion of sediments during soil formation.