A New Calibration Equation for Diviner2000 Capacitance Probe Accounting for Soil Shrinkage Characteristic Curve and Estimation of Parameters on the Basis of Soil Physical Properties

Real-time measurements of soil water status are quite often used for irrigation scheduling and particularly in precision irrigation, in order to identify the exact timing and amount to supply to crops according to their water requirements. Diviner2000 capacitance probes, measuring the apparent soil dielectric permittivity, have been extensively used in the last decade. Several studies have shown that, for different soils, there is a relationship between the volumetric soil water content (SWC) and the scaled frequency (SF) measured by the sensor. However, for swelling/shrinking clay soils, for which bulk density changes with soil water content, there is a lack of knowledge on how these varia…