Site-Specific Calibration of EnviroScan Capacitance for Estimating Soil Water Content. (S01-jabro633721-poster)
Authors:
J.D. Jabro* - Washington State Univ.
B.G. Leib - Washington State Unive.
Abstract:
EnvirScan sensors have the potential to monitor soil moisture content continuously and at various depths. Our objectives were to specific-site calibrate the EnviroScan capacitance using in-situ neutron probe calibrated with gravimetrically measured soil water content, then statistically compare the calibrated results with those estimated by the default equation using three years of data. The average water contents of the soil profile estimated by the EnviroScan capacitance were used to develop the calibration equation and to assess accuracy evaluation with the neutron probe measured calibrated values. A site calibration equation was developed using the 1998 water content and sensors output. The calibration equation was then statistically evaluated using both 1999 and 2000 soil water contents. The statistical analysis indicated that considerable discrepancies existed between soil water contents estimated by the site-calibration equation and those estimated by the default uncalibrated equation as they were compared with those of the neutron probe values. The site calibration equation was also found to give rather accurate estimates of absolute values of volumetric soil water content. Therefore, the need for individual soil specific calibration is essential for the most accurate absolute soil water content measurements as confirmed by previous studies that most of these sensors are sensitive to various soil properties and conditions.
Speaker Information: Jay Jabro, Washington State Univ., Department of Biosystems and Agricultural Engineer, Prosser, WA 99350; Phone: 509-786-9242; E-mail: [email protected]
Session Information: Wednesday, November 5, 2003, 4:00 PM-6:00 PM Presentation Start: 4:00 PM (Poster Board Number: 1638)
Keywords: EnviroScan Capacitance; Soil Water Content; Neutron Probe Measurements; Site-Specific Calibration Equation
