(MDPI, 2018) López Aldaba, Aitor; López Torres, Diego; Campo-Bescós, Miguel; López Rodríguez, José Javier; Yerro Lizarazu, David; Elosúa Aguado, César; Arregui San Martín, Francisco Javier; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; López-Amo Sáinz, Manuel; Ingeniaritza Elektrikoa eta Elektronikoa; Landa Ingeniaritza eta Proiektuak; Institute of Smart Cities - ISC; Institute on Innovation and Sustainable Development in Food Chain - ISFOOD; Ingeniería Eléctrica y Electrónica; Proyectos e Ingeniería Rural
Soil moisture content has always been an important parameter to control because it is a
deterministic factor for site-specific irrigation, seeding, transplanting, and compaction detection.
In this work, a discrete sensor that is based on a SnO2–FP (Fabry-Pérot) cavity is presented and
characterized in real soil conditions. As far as authors know, it is the first time that a microstructured
optical fiber is used for real soil moisture measurements. Its performance is compared with a
commercial capacitive soil moisture sensor in two different soil scenarios for two weeks. The optical
sensor shows a great agreement with capacitive sensor’s response and gravimetric measurements,
as well as a fast and reversible response; moreover, the interrogation technique allows for several
sensors to be potentially multiplexed, which offers the possibility of local measurements instead of
volumetric: it constitutes a great tool for real soil moisture monitoring.
