Erodibility of major soil sub-groups of eastern region of India

Erosion index (EI) was determined for surface as well as subsurface layers of twenty six soil subgroups of eastern India. Soil erodibility was related to various physicochemical properties of the soils. In 0–15 cm layers, the highest erosion index 45.86 was observed in Typic Ustipsarnment followed by Vertic Ustochrept 41.62, Aeric Haplaquept 39.16 and the lowest 2.99 in Rhodic Paleustalf. In 15–30 cm soil depth it varied from 36.89 in Aeric Fluvaquent to 7.26 in Typic Paleustalf. In the 30–150 em layer, it varied from 40.85 in Aeric Fluvaquent to 8.29 in Ultic Paleustalf. Significantly higher value of E1 was observed for 0–15 cm soil depth and no significant difference in E1 was observed between 15–30 and 30–150 cm soil layers. In general erosion index decreased with soil depth. A highly significant and negative relationship of erosion index with clay, silt + clay, maximum water holding capacity and highly significant, and positive relationship with sand and dispersion ratio were observed. As the dispersion ratio increased, erosion index increased indicating susceptibility of these soils to water erosion. Based on the erodibility characteristics of the major sub-groups of eastern region, it is suggested that all dominating soil subgroups of eastern region need some kind of soil and water conservation measures.