Physico-chemical and Hydraulic Characteristics of Soils of Major Sub-Groups of Eastern India Singh Ravender1,*, Kundu D.K. Directorate of Water Management, Chandrasekharpur, Bhubaneswar, 751 023, Orissa. *Corresponding author (Email: rsingh.iari@gmail.com)
1Present address Division of Agricultural Physics, Indian Agricultural Research Institute, New Delhi, 110 012. Abstract Physical, chemical and hydraulic characteristics of 26 dominating soil sub-groups of Eastern India were determined and soil water functional relationships developed. Most of the fine textured soils belonged to Inceptisols, Vertisols and Mollisols, and the coarse textured soils belonged to Alfisols and Entisols subgroups. All the soil sub-groups of Entisols and most of the Inceptisols had very high erosion index. Dispersion ratio and erosion index data revealed that soils of sub-groups of Entisols and Inceptisols are prone to erosion, and soil conservation measures need to be taken on priority basis for them. At 0.033 MPa, highest water was retained by Typic Haplustepts and the lowest by Typic Ustipsamments. Similarly at 1.5 MPa, highest amount of water was retained by Typic Haplustepts and the lowest by Typic Ustipsamments. Highest available water at all the depth was found in Typic Haplustepts and the lowest in Typic Ustipsamments. In comparison to Alfisols and Entisols, more water was retained by Inceptisol, Vertisol and Mollisol soil sub-groups at 0.033 and 1.5 MPa. The highest saturated hydraulic conductivity was observed in Typic Ustipsamments and the lowest in Aeric Fluvaquents. Highest air entry suction at all depths was found in Typic Haplustepts and the lowest in Typic Ustipsamments. Out of 26 soil sub-groups, soils of 15 had very high, 6 high, 3 medium and 2 low water storage capacity. For ψ-θ functional relationship, the value of exponent for θ varied from –3.369 to –7.448. The highest exponent values were observed for Aeric Ochraqualf, where these varied from –3.369 to –5.037 and the lowest in Vertic Haplustept (–6.329 to –7.448). Generally, values of exponent for θ decreased as the soil depth increased. The value of exponent varied from 9.74 to 17.90 for K-θ relationship, from 5.37 to 9.45 for D-θ, and 4.369 to 8.448 for specific water capacity and water content relationships. Based on the data obtained from the present study, amelioration of erosionprone soils and judicious application of irrigation for different soil-groups are suggested for enhancing their water use efficiencies. Top Keywords Soils of eastern India, available water, hydraulic conductivity, diffusivity, specific water capacity, dispersion ratio, erosion index. Top |