Characterization of Vertisols in Semi-arid Tropical Region of Chinnapalem Village of Guntur District in Andhra Pradesh

Abstract

Eight representative pedons were selected from the study area and the soil samples collected from each horizon in these eight pedons were analysed for physical properties viz., particle size analysis, soil density, water holding capacity, volume expansion, pore space, COLE and LOI; physico-chemical properties like pH, EC and organic carbon; electro-chemical characteristics such as CEC, exchangeable bases, base saturation and ESP and chemical properties such as available macronutrients (N, P2O5, K2O, and S) and micronutrients (Zn, Cu, Fe and Mn). The Pedons 2, 3, 5, 6, 7 and 8 exhibited an increasing trend in clay content with depth. However, no specific trend with depth was observed in the remaining pedons. Physical constants like water holding capacity, loss on ignition and volume expansion followed the trend of clay content. Bulk density showed an increasing trend with depth corresponding to decreasing organic carbon with depth in all the pedons. COLE values not followed any specific trend with depth in any of the pedons. The soils were neutral to moderately alkaline in reaction, non-saline to slightly saline in nature and low to medium in organic carbon. The CEC values were medium to high and exchange complex was dominated by Ca2+ followed by Mg2+, Na+ and K+. Soils were low to medium in available nitrogen, low to high in available phosphorous, high in potassium and deficient to sufficient in available sulphur. However, the soils were sufficient in DTPA extractable Cu, Fe and Mn and deficient to sufficient in DTPA extractable Zn.