Scientific synthesis of the DIGISOIL project

Since 2002, the European Commission considers the soil as a non-renewable resource threatened by natural hazards and human activities. Erosion, organic matter decline, contamination, sealing, compaction, salinisation, floods and landslides have been identified as the main soil threats. The implementation of the Soil Thematic Strategy (COM232, 2006) implies that Member States individuate risk areas for erosion, organic matter decline, compaction, salinisation and landslides. Among the main soil and soil-related parameters to be considered by Member States for delineating risk areas, soil texture, soil water content – and related hydraulic properties, bulk density and soil organic matter, impact crucially many soil functions, so that these properties have to be considered as a first priority. In particular, threats to soil like organic matter decline, erosion or compaction processes, water stocks management should be addressed urgently for preserving future agricultural resources. The purpose of the DIGISOIL project was to develop pertinent, reliable, and cost-effective geophysical solutions for mapping soil properties. Considering recent advances in equipment and signal processing, collecting soil information at the catchment scale needs the deployment of geophysical sensors of different nature. The identified sensing systems included the ground-penetrating radar (GPR), electrical resistivity tomography (ERT), electromagnetic induction (EMI), seismics, and airborne hyperspectral). Some tests were also realized with magnetics. This panel of methods are at the basis of the DIGISOIL’s mapping tools designed to provide inputs to DSM applications. The activities presented here were thus focused on (i) adapting, testing, and validating the geophysical technologies, (ii) establishing correlations between measured geophysical parameters and soil properties involved in soil functions/threats such as erosion, compaction, organic matter decline, (iii) evaluating the societal impact of the developed tools by investigating their relevance to end-user needs, their technical feasibility, and their cost-effectiveness.