Asian Journal of Microbiology, Biotechnology & Environmental Sciences Paper

FIELD EVALUATION OF CAPACITANCE PROBE TO MEASURE SOIL WATER CONTENT

ABOUTALEB HEZARJARIBI, HEINZ SOURELL, GHORBAN GHORBANI NASRABAD, ABDOLREZA GHARANJIKI AND MEYSAM. ABEDINPOUR

Abstract

Capacitance probe sensors are a popular electromagnetic method of measuring soil water content. In this study EnviroSCAN capacitance sensors were calibrated for a sandy and loamy sand soils and the water contents estimated by calibrated equation and with those estimated by the manufacturers default (uncalibrated) equation were statistically compared. Results demonstrated that calibrated EnviroSCAN sensor could be used as the standard instrument to measure soil water content in loamy sand, but it was not found as a reliable method to measure soil water content in sandy soil. The uncalibrated equation of both of soil textures appeared to consistently understimate soil water content. A large discrepancies existed between calibrated and uncalibrated values for both of soil textures. Calibrated values of soil water content in loamy sand profile were close to those measured by the soil samples. Calibration of EnviroSCAN capacitance sensor found to give more accurate estimation of soil water content values, and essential to improve sensors performance, compared to those obtained from the uncalibrated equation in loamy sand soil.