Real -Time Drainage Fluxes From The Root Zone By Using Capacitance Probe Data

A collaborative, Tri-State Salinity research project is being undertaken in the Riverland and Sunraysia to investigate the mechanism of soil salinity build up in the root zone and the resultant economic loss (Schrale and Biswas 2004). One of the aims of this project is to estimate the rate of deep drainage (DD) from the root zone. In this paper we present two approaches for assessing DD from data generated by multi-sensor capacitance probes, which are now widely used for irrigation scheduling in those horticultural districts. Capacitance probes utilise Frequency Domain Reflectometry (FDR), which is based on dielectric properties of soil water.