Soil salinity monitoring and detection of obstructed drainage pipes in the B-XII irrigation district (SW Spain) using electromagnetic induction sensing and inversion.

Inversion of electromagnetic induction (EMI) signals is increasingly used for monitoring soil salinity in irrigated fields. In the B-XII irrigation district (SW Spain) the build-up of high salt concentrations in the topsoil is often related with a deficient performance of the underlying drainage system resulting in higher-than-average soil moisture conditions and salinization. This work aims at using EMI sensing and inversion to identify and localize problems (e.g. obstruction) with the drainage system in a 12.5 ha irrigated field in the B-XII irrigation district. The identified salinity hotspots in the EMI images are further validated using remotely sensed NDVI data and detailed information obtained during the cleaning of the drainage system, in addition to hard soil data. This study shows that EMI sensing and inversion can pinpoint problems with the drainage system that result in salinity hotspots and identify areas where the drainage system should be cleaned or substituted.

 

This work is funded by the Spanish State Agency for Research through grants PID2019-104136RR-C21 and PID2019-104136RR-C22 and by IFAPA/FEDER through grant AVA2019.018.