Time Domain Reflectometry (TDR) calibration for estimating soil solution concentration [Calibração da Reflectometria no Domínio do Tempo (TDR) para a estimativa da concentração da solução no solo]

Abstract

Time Domain Reflectometry (TDR) is a reliable method for in-situ measurements of the humidity and the solution concentration at the same soil volume. Accurate interpretation of electrical conductivity (and soil humidity) measurements may require a specific calibration curve. The primary goal of this work was to establish a calibration procedure for using TDR to estimate potassium nitrate concentrations (KNO 3) in soil solution. An equation relating the electrical conductivity measured by TDR and KNO 3 concentration was established enabling the use of TDR technique to estimate soil water content and nitrate concentration for efficient fertigation management.