Terahertz Frequencies: A New Frontier in 24/7 Soil Sensing (Initial Results)

Terahertz (THz) waves, renowned for their unique penetration, absorption, and reflection properties, have emerged as key technologies for the future, offering boundless potential across diverse fields. This paper focuses on THz-based imaging for 24/7 plant health monitoring, presenting findings from an experimental study. The study commences with soil experiments conducted within the frequency range of 275−325 GHz, utilizing a THz-VNA testbed in a bistatic setup to examine clay soils of varying ages. Moistening the soil with 232 and 464 ml water facilitates the assessment of its plasticity, with 25 positions targeted within the clay soil sample container to capture comprehensive data around the clock. Additionally, the water content of raw clay soil samples is examined to further enrich the study.