Characterization and classification of soils of the Ganjigatti sub-watershed in Dharwad district of Karnataka

Abstract

Nine typical pedons representing uplands, midlands and lowlands in the Ganjigatti sub-watershed, Karnataka, were selected and studied for their morphological, physical and chemical properties in relation to variation in physiography during 2021-23. The profile development was lowest in the uplands and highest in the lowlands. The upland soils (pedons 1, 2, 3 and 4) had a medium, moderate and subangular to angular blocky structure, shallow deep, yellowish-red to strong brown colour (5 YR to 7.5 YR), sandy clay loam texture, strongly acidic to neutral pH, 5.20 to 38.48 cmol(p+)kg-1 CEC and medium base saturation. Moving to midland soils (pedons 5, 6 and 7), they exhibited a fine to medium, moderate structure characterized by granular to sub-angular blocky formations. These soils were moderately shallow to moderately deep, with a dark brown to very dark brown hue (7.5 YR to 10 YR), sandy clay to clay texture, neutral pH, 18.52 to 41.54 cmol(p+)kg-1 CEC and high base saturation. Descending to the lowland regions, the soils (pedons 8 and 9) were fine, strong, granular to angular blocky, very deep, with a brown to very dark brown colour (10 YR), clay texture, neutral to alkaline pH, 16.26 to 51.50 cmol(p+)kg-1 CEC and high base saturation. Based on soil profile development and diagnostic characteristics, we classify the soils at the sub-group level as Lithic Ustorthents (pedons 1 and 4), Typic Ustorthents (pedons 3 and 7), Lithic Haplustalfs (pedon 2), Typic Haplustalfs (pedon 6), Typic Haplustepts (pedon 5), Vertic Haplustepts (pedon 8) and Typic Haplusterts (pedon 9).