Inefficiencies in current agriculture practices result in the overuse of scarce resources, while limiting achievable crop production. Precision agriculture systems can lead to a more judicious use of agriculture resources and enable higher crop yield. This presentation will focus on the design, development and demonstration of a radio-frequency, long-range, passive sensing platform that enables low-cost biodegradable sub-surface soil sensor nodes. The research encompasses the design and characterization of biodegradable soil moisture sensors, as well as the design of high-performance microacoustic resonators and their integration with an antenna to enable long-range passive readout of capacitive sensors.