Physico-chemical determinant parameters in the color of vertisolization and tirsification processes

Abstract

A statistical analysis is carried out on the influence that certain physico-chemical parameters exert on tirsification and vertisolization pedological processes that occur under certain geomorphological conditions in Andalusia region (Spain). Both processes occur on a parent material with high contents in smectitic clays, massive and uniform and contrasting climatic conditions where periods of humidity and those of drought  alternate. Chromic Vertisol (tirsificated) versus Calcium Vertisol (vertisolizated) (FAO, 2015) shows a greater interrelation between parameters given its greater weathering. Organic carbon controls a large part of its physical-chemical processes where the lateral washing of salts and carbonates together with manganese, always in a lower concentration than iron, play a definitive role in the blackening of its horizons. The chemical fertility is always low and  the geomorphological conditions seems to account for its agricultural capacity.