Chemical Science & Engineering Research
Title
Elemental Geochemistry of Soils in Relation to Lithology and Topography : A Case Study from Penneru River Basin, Kadapa District, Andhra Pradesh
Authors
Dwaram Venkata Sujatha,*a Moganti Venkata Subbaiah Naidu,a Bhaskara Phaneendra Bhaskar,b Doddaga Subramanyam,a Balam Ravindranatha Reddya and Timmivujjula Giridhara Krishnaa
aDepartment of Soil Science and Agricultural Chemistry, Sri Venkateswara Agricultural College, Tirupathi, Andhra Pradesh-517 502, India.
bICAR-NBSS&LUP, Regional Centre, Bangalore, Karnataka-560024, India.
*Corresponding author E-mail address: sujathadwaram42@gmail.com (Sujatha D.V.); mvsnaidu66@gmail.com (M. V. S. Naidu)
Article History
Publication details: Received: 20th December 2021; Revised: 8th February 2022; Accepted: 8th February 2022; Published: 28th February 2022
Cite this article
Sujatha D.V.; Naidu M.V.S.; Bhaskar B.P.; Subramanyam D.; Reddy B.R.; Krishna T.G. Elemental Geochemistry of Soils in Relation to Lithology and Topography : A Case Study from Penneru River Basin, Kadapa District, Andhra Pradesh. Chem. Sci. Eng. Res., 2022, 4(9), 1-8.
Abstract
In part of the Pennar basin, YSR Kadapa district, Andhra Pradesh, soil transect studies on Gandikota formations with six profiles were conducted. These studies were conducted to examine differences in weathering patterns of soils in relation to lithology and topography. The soils on Gandikota formations have ochric epihorizons ranging in color from reddish yellow to brown and brown to dark brown cambic horizons. Middle slopes show lithological discontinuities with erratic sand-to-silt ratios. It seems that these soils are slightly acidic to strongly alkaline with a high capacity for cation exchange, exchangeable sodium percentage, and a ratio of CEC/clay greater than 0. 7. Clayeness (mAl2O3/mSiO2), calcification, and sodification are dominant pedogenic processes with low to moderate variability of major oxides in the Bss horizons and moderate variability of alkali oxides. According to the CAL MAG index, the paleo-mean annual rainfall estimate is 1261.05 ± 94.98 mm, compared to 650 mm at present. Log (Na2O/K2O) versus log (SiO2/Al2O3) plots show low SiO2 content in lower slope soils, indicating sediment from immature litharenites and arkose fragments. Based on the A-CNK-FM ternary diagram, these soils are moderately weathered on lower and middle slopes. Transect soil studies in the Penneru river basin will provide geochemical clues that vary with topographic positions and provide insight into soil properties at the landscape level.
Keywords
bivariate plot; cuddapah basin; geochemistry; shrink-swell soils; weathering indices; ternary diagram
