Wstępna ocena możliwości szacowania potrzeb wodnych roślin na podstawie prostych pomiarów meteorologicznych

On the basis of the measurements recorded by seven automatic meteorological stations, evapotranspirati on (ET 0 ) was calculated according to the formula devised by Hargreaves and Hargreaves, modified by Droogers and Allen (H and HDA) and Grabarczyk (G). The obtained results were compared with the reference formula recommended by FAO, which adopted the Penman - Monteith formula (PM). A high correlation between the reference model and the simplified formulas was shown. The differences relate to the level of evapotranspiration (ET 0 ) worked out with the various formulas. The Hargreaves model gives a higher value in comparison with the PM formula, whereas Grabarczyk’s model (G) makes it lower. The application of the Hargreaves model modified by Doogers and Allen produced results closest to the reference model. In order to apply the Penman - Monteith model in practice, a lot of meteorological parameters are required, which is a serious limitation. The simpler methods might be used, but they require further investigations in our climatic conditions in order to verify their empirical factors.