Comparison between the evapotranspiration of alfalfa measured by eddy covariance and estimated by FAO 56 method in Central Italy

The objective of this study is the comparison between crop evapotranspiration measurements by eddy covariance (ETEC) and estimates by FAO-56 method (ETC). An open patch eddy covariance (EC) system has been installed in the middle of an alfalfa farmland in Central Italy. The evapotranspiration was measured by the EC system during the growing season of the year 2009. For the same period crop evapotranspiration was also calculated as the product between reference evapotranspiration (ET0) estimated by the FAO Penman-Monteith equation and the factor Kc•Ks (where Kc, crop coefficient; Ks, water stress coefficient, FAO-56 method).