A system and method for reducing moisture of a fibrous material includes applying microwave radiation combined with RF to the fibrous material to heat and evacuate moisture from the fibrous material during a heating cycle and optionally alternating heating cycles with drying/cooling cycles. The fibrous material can be, for example, sawn or dimensional lumber. The application of alternating microwave and RF in a controlled and continuous process advantageously mimics the heating, rewetting and drying cycles of a conventional kiln without the need for batch processing. Accordingly, a faster and more cost-efficient drying process is possible with no defects imparted to the wood in the process.