A system for measuring temperature and dielectric properties of soil and other semi-solid materials on-the-go uses a long-wearing non-ferrous wear plate with two metal prongs supported by the wear plate to measure dielectric properties. The metal prongs each have a mounting end soldered to a printed circuit board containing a capacitance sensor circuit. The metal prongs have exposed ends arranged to contact the semi-solid material being measured. The sensor circuit has an oscillation frequency of 50 to 100 MHz to allow rapid dielectric measurements to be made as the sensor moves through the semi-solid material. In one embodiment, the system includes an implement for traversing a field, a shank with a leading edge for opening a furrow in soil, and a spring-loaded mounting system for biasing the wear plate downwardly relative to a shank to maintain a consistent pressure of the wear plate and metal prongs against the soil.
