A FIBEROPTIC PROBE TO SIMULTANEOUSLY DETERMINE SOIL WATER CONTENT AND SOIL TEMPERATURE

PRESENT SOIL FIELD INSTRUMENTS DETERMINE ONLY ONE SOIL PHYSICAL PARAMETER AT ONE TIME AND AT ONE POINT. THE COMBINATION OF FIBEROPTIC TECHNIQUES WITH INFRARED AND VISIBLE OPTICAL SENSORS PROVIDES A MEANS FOR PROBING, VIEWING AND SENSING SIMULTANEOUSLY IN SITU SOIL PHYSICAL CHANGES. A FIBEROPTIC DEVICE WILL BE DEVELOPED TO INVESTIGATE IN SITU SIMULTANEOUS CHANGES OF SOIL WATER CONTENT AND SOIL TEMPERATURE WITHIN THE SOIL PROFILE. COMMERCIAL FIBEROPTIC BUNDLES, OPTICAL SENSORS, AND TEMPERATURE SENSORS WILL BE USED IN PHASE I. THE PROBE WILL BE TESTED AND CALIBRATED USING SEVERAL SOIL TYPES AND ARANGE OF SOIL TEMPERATURES IN THE LABORATORY. RESULTS WILL ESTABLISH THE OPTIMUM MULTI-DEPTH PROBE DESIGN AND CALIBRATION PROCEDURES THAT CAN BE USED IN PHASE II TO MEASURE SEVERAL PARAMETERS SIMULTANEOUSLY AT DIFFERENT SOIL PROFILE DEPTHS. THE FINAL DEVICE WILL OFFER A REDUCTION IN TIME AND COST OF TAKING MULTIPLE PHYSICAL MEASUREMENTS IN THE FIELD. A COMMERCIAL MULTI-PARAMETER SOIL PROBE SENSING SYSTEM WILL PROVIDE AGRICULTURAL SCIENTISTS WITH ONE MULTIPURPOSE RESEARCH INSTRUMENT AND PROVIDE FARMERS WITH A FIELD EVALUATION TOOL FOR IRRIGATION AND FARM MANAGEMENT DECISIONS.