Stress features in Terra Rossa soil under traditional olive cultivation: a micromorphological and mineralogical characterization

Abstract

This study analyzes the micromorphological and mineralogical properties of a Terra Rossa soil under a traditional Mediterranean olive grove. It highlights the microscopic and sub-microscopic features generated by the permanent crop cover. The study area, where the land use has remained unchanged for the last 150 years, is near Sassari (Sardinia, Italy) and is characterized by dominant Terra Rossa developed on Miocene marine limestone. Two soil profiles were opened and described in July 2009, 1 under the canopy of an olive tree and 1 between the trees. Chemical and physical analyses were carried out. Undisturbed aggregates were collected from all the sampled horizons for thin section and scanning electron microscope (SEM) analysis, complemented by mineralogical analyses (X-ray diffractometry, XRD). The results obtained highlighted the effects of vigorous bioturbation and stress actions that have occurred on the pedogenetic features inherited from complex genetic processes.