CHARACTERIZATION OF BENCHMARK SOIL SERIES DEVELOPED ON BASALT AND LIMESTONE PARENT MATERIALS IN HYDERABAD-KARNATAKA REGION

Abstract

A study was undertaken to characterize the benchmark soil series developed on Basalt (Raichur series) and Limestone (Kagalgomb series) parent materials in Hyderabad-Karnataka region. In Raichur series, the colour varied from dark grey (10YR 4/1) to very dark greyish brown (10YR 3/2) and in Kagalgomb series, very dark greyish brown (10YR 3/2) colour was observed. In Raichur series and Kagalgomb series, texture was clay, bulk density varied from 1.25 to 1.35 Mg m-3 and from 1.20 to 1.32 Mg m-3, respectively. Water holding capacity of Raichur series ranged from 51.57 to 55.43 per cent whereas in Kagalgomb series it ranged from 49.57 to 55.46 per cent. The pH showed that moderately alkaline (7.8-8.4) in Raichur series and strongly alkaline (8.7 to 9.2) in Kagalgomb series. Organic carbon content in Raichur series ranged from 0.14 to 0.44 per cent and in Kagalgomb series ranged from 0.26 to 0.93 per cent. Available nitrogen (N) was low (167 to 189 kg ha-1) in Raichur series and low to medium (246 to 448 kg ha-1) in Kagalgomb series. Available phosphorus (P2O5) was low to high i.e. 8.90 to 81.75 kg ha-1 in Raichur series and 20.13 to 80.53 kg ha-1 in Kagalgomb series; the available potassium (K2O) content ranged from 450 to 485 kg ha-1 in Raichur series and 395 to 671 kg ha-1 in Kagalgomb series. The DTPA extractable Fe, Cu and Mn were sufficient and Zn was deficient in both the Benchmark soil series.