USING SCINTILLOMETRY TO ESTIMATE ACTUAL SUGAR BEET EVAPOTRANSPIRATION

Water availability is one of the key factors in the production of plant biomass and is directly related to the evapotranspiration (ETa) of a stand. This article describes one of the modern methods of determining ETa using scintillometers. Scintillometry is an optical method that uses the principle of scintillations of air over the surface. The scintillations are "measured" based on the scattering of an infrared beam. With additional measurements of solar radiation, air temperature, wind speed, and soil heat flux, we can determine ETa - the amount of water evaporated from the stand in mm of water column. Assessment of ETa compared to precipitation is an easy way to determine the main parts of water balance or deficit at a given location. This study focuses on the evapotranspiration of sugar beet in the Hana region (location Polkovice) in 2017. It describes the development of reference evapotranspiration and measured ET, throughout the season. During the vegetation period (13 March 2017-26 November 2017), ETa estimated by scintillometry was 521 mm and precipitation covered 471 mm.