Characterization and Classification of Soils in Semi-arid Region of Tatrakallu Village of Anantapuramu District in Andhra Pradesh

Abstract

Twelve typical pedons representing major landforms in semi-arid ecosystem of Tatrakallu village, Anantapuramu district of Andhra Pradesh viz., plains and uplands originated from granite-gneiss and limestone parent materials were studied for their morphological, physical and chemical properties, soil genesis, taxonomy and nutrient status. The soils were slightly acidic to strongly alkaline (6.5 to 8.9) in reaction, non-saline (0.01 to 1.90 dS m-1), shallow, deep and very deep in depth and had isohyperthermic temperature and ustic soil moisture regimes. The texture, organic carbon (OC), cation exchange capacity (CEC) and base saturation were ranged from loamy sand to clay, 1.6 to 6.7 g kg-1, 7.0 to 50.6 cmol(p+)kg-1 and 57 to 99%, respectively. The soils were low (65 to 265 kg ha-1) in available nitrogen, low to high in available phosphorus (1.2 to 84.8 kg P2O5 ha-1) and potassium (63 to 693 kg K2O ha-1), deficient to sufficient (6.6 to 54.8 mg kg-1) in available sulphur, deficient to sufficient in DTPA extractable Zn, Fe and Mn and sufficient in DTPA extractable Cu. Pedons 1, 2 and 6 were placed under Entisols due to absence of sub-surface diagnostic horizon and were classified as Lithic Ustorthents and Typic Ustifluvents whereas pedons 3, 5 and 8 were grouped under Inceptisols due to presence of cambic (Bw) sub-surface diagnostic horizon and classified as Lithic Haplustepts, Typic Haplustepts and Fluventic Haplustepts. However, pedons 4 and 7 were classified under Alfisols due to presence of argillic horizon (Bt) as Typic Haplustalfs and Lithic Haplustalfs. The remaining pedons were placed under Vertsiols due to presence of more than 30% clay in all the horizons, presence of slickensides and wedge shaped aggregates in sub-surface horizons, cracks in surface horizons and were classified as sodic Calciusterts, sodic Haplusterts, Typic Haplusterts and Leptic Haplusterts.