A New Approach in the Study of Vertisol Morphology

A new approach in the study of Vertisol morphology exhibiting active role of the process of haploidization by argillipedoturbation, was attempted to describe typifying Vertisol pedons as well as soil pedons of Vertic intergrades.

Vertisol soil pedons of Umbraj, Otur and Linga soil series occurring in semi-arid and sub-humid parts of Maharashtra state were observed to be characterised by wide open shrinkage cracks and gilgai micro-relief on the surface while Ac soil profiles were characterised by cyclic or intermittent A₁ horizon with unique pedality showing prolate dispheric intersecting slickensides in the upper parts forming wedge-shaped peds or parallelepipeds in the lower part.

Soil pedons of Sawargaon soil series belonging to Vertic sub-group of Ustropepts great-group also occurring in semi-arid part along with Umbraj and Otur soil series were found to exhibit only wide open shrinkage cracks but no gilgai micro-relief on their surface while ABC profiles expressed active role of the process of horizonation with the development of Cambic B having moderately developed angular blocky structural profile with shiny pressure face on angular blocky peds.

The cyclic soil pedons of Umbraj, Otur and Linga series were measured as small or medium or large according to the measure of the one-half of cyclic or intermittent A₁ horizon bearing a direct relationship to the linear frequencies of “Puffs” and “Shelves” in gilgai micro-relief.

The topography of the lower boundary of the cyclic or intermittent sub-horizons of A₁ horizon has been described in terms of amplitude and defined as low, medium or high amplitudes while the shape of the intermittent horizon has been defined as tongued or wavy or smooth comparing the horizontal and vertical stretch of the cycle. Since the unique pedality of cyclic or intermittent horizons are pedogenic and diagnostic characteristics of Vertisol morphology, the letter “V” has been suffixed to the designated horizons and sub-horizons in Vertisol soil pedons as well as in soil pedons of Vertic sub-groups.