THERMAL DISINFECTION OF SOILS WITH RADIOFREQUENCY POWER

New methods to utilize radiofrequency (RF) power are being investigated as physical (non-chemical) thermal methods for disinfecting and disinfesting various foods and non food materials, including agricultural soils.1-4. The RF process operates with electric power that generates a rapidly oscillating electric field between parallel electrodes (RF cavity) forcing dipole and induced dipole molecules to align and reorient to the changing field, causing friction that converts to heat. Many industrial food processes have been proposed, studied, or applied with RF power. Today, RF applications are somewhat limited to frozen foods, fruit juices, post-baking drying, and some pasteurization processes. This is due mostly to the high cost of RF systems ( ~ $ 2,000/kW or higher) as well as to the many unknowns regarding the RF properties of foods and other materials. At UC Davis, new bands of the RF spectrum (few kHz to < 10 MHz) have been studied and tested successfully allowing new RF systems to be designed and engineered based upon solid state electronics. These new RF systems can be built with significant cost reduction ( ~ $200-300/kW) and are capable of operating with>90 % overall energy-use efficiencies. With these new RF systems, disinfection efficacy for fungi and nematode