Comparison of instruments for geoelectrical soil mapping at the field scale
Résumé
Precision Agriculture (PA) is a new application for sub-surface geophysics and can be classified in the field of environmental applications. The need of precise soil information with high spatial resolution is one of the many challenges of PA. Geoelectrical methods have shown their capability to detect spatial variation of important physico-chemical soil parameters in an efficient way. However, relationships between the electrical parameters (electrical conductivity or resistivity) and other soil properties are not always consistent over different fields. This can, to some extent, be due to the characteristics of instruments used for soil mapping. However, limited amount of research has addressed this issue. In this study, seven instruments for mobile mapping available on the market were investigated (ARP03, CM-138, EM38, EM38-DD, EM38-MK2, OhmMapper, Veris 3100). Instruments were employed under field conditions and results were compared with a high accuracy reference. Additional investigations were made concerning temperature drift and seasonal influences. Market differences between the instruments were found which have to be taken into account when geoelectrical surveys are planned or interpreted.
Mots clés
Electrical resistivity
electrical conductivity
electromagnetic induction
direct current method
galvanic coupled resistivity method
capacitive coupled resistivity method
accuracy
depth of investigation
temperature drift
seasonal influences
ARP03
CM-138
Earth Resistivity Meter
EM38
EM38-DD
EM38-MK2
GeoTom
OhmMapper
Veris 3100
Origine : Fichiers produits par l'(les) auteur(s)
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