Click on the underlined title to access the document or go back to the Search Results screen to download the PDF version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

Two capacitance probes, the ECH2O and C-probe, have recently becomes available for monitoring soil water content. The relatively low cost ECH2O probe was calibrated, evaluated, and its performance was compared to the more expensive C-probe for real time monitoring of soil water status. Two calibration models were developed for a fine sand soil (> 95% sand, <3% clay, <1% organic matter) of central Florida. In Model 1, a linear regression was developed between probe output in millivolts (mV) and measured soil core volumetric water content at 6 moisture levels (0.0133, 0.0267, 0.04, 0.0533, 0.08, and 0.10 cm3 cm-3). Model 2 fits Air-Water normalization of mV values and measured soil core volumetric water content at 6 moisture levels. Performance of the models was found to be satisfactory. With Model 2 validation, observed R2, average prediction accuracy, standard error of prediction, and root means square errors were 0.98, 88%, 0.0042 cm3 cm-3 and 0.0041 cm3 cm-3, respectively. Both ECH2O and C-probes responded well with respect to irrigation, rainfall, and water uptake by the plants. Thus, this relatively low cost ECH2O probe has shown potential for continuous monitoring of soil moisture status in a fine sand soil of central Florida.