Using proximal electromagnetic/electrical resistivity sensors to assess soil health
Résumé
Soil health assessment can be understood as a synthetic approach using complex indicators including a variety of soil physical and biological characteristics. The electrical/electromagnetic properties, whilst limited in number, are directly linked with some of the most relevant soil parameters characterizing soil health. Their measurement can be implemented through non-invasive techniques allowing to map with a fine mesh the whole surface in question and to recognize the vertical distribution of layers. They offer thus a 3D holistic approach. After a short summary of the soil health concern, the chapter recalls the definitions of the three relevant properties (conductivity, permittivity, magnetic susceptibility), and details the different electrical and electromagnetic techniques used in the soil domain. Two case studies in temperate and arid climates illustrate what can be obtained when using these techniques. A short discussion underlines the perspectives offered by a holistic approach to evaluate soil health characteristics from geophysical measurements.