A multidisciplinary study of salt-affected soil in the coastal areas of Southeastern Sardinia (Italy)

Saline soils represent one of the major constraints to agricultural productivity in Mediterranean coastal alluvial plains, with significant implications for the introduction of high-value crops such as avocado (Persea americana). The coastal alluvial plain of the Flumendosa River (southeastern Sardinia) is a heterogeneous environment where depositional dynamics, marine intrusion, and water management strongly influence the distribution of soil salinity and related pedological properties. This study presents an integrated approach to characterising salt-affected soils combining pedological surveys, field investigations, laboratory analyses, and remote sensing techniques. Measurements of key salinity parameters, particle size distribution and mineralogical investigations, with particular focus on clay components through X-ray diffraction (XRD), aimed to identify mineral assemblages responsible for salt retention and sodicisation. Mineralogy analysis was coupled with Scanning Electron Microscopy (SEM) to investigate the micromorphology and formation processes of carbonate concretions. In parallel, processing of multispectral satellite data allowed the derivation of salinity-related indicators and the spatial mapping of soil salinity variability.
The integration of these complementary datasets enabled the development of a functional soil zonation for the Flumendosa plain, providing insights into their suitability for avocado cultivation and supporting the identification of appropriate management and mitigation strategies. The results highlight the effectiveness of a multidisciplinary approach in guiding sustainable agronomic decisions in salt-affected coastal areas.