Using the dual-K_c approach to model evapotranspiration of Albarino vineyards (Vitis vinifera L. cv. Albarino) with consideration of active ground cover.

摘要

This research aims at testing the dual crop coefficient approach to model the evapotranspiration of the traditional Galician "semi-trellised" vineyard of Vitis vinifera cv. Albarino with active ground cover. A separate calculation of soil evaporation, transpiration of the vine crop and transpiration of the active ground cover was conducted. Three irrigation treatments - rain-fed, surface and subsurface drip irrigation - were conducted during three crop seasons (2008-2010). The SIMDualKc model, that performs the soil water balance with the dual K_c approach, was applied for estimating crop evapotranspiration (ET_c) by calculating a basal crop coefficient for the vine crop (K_{cb full}), another for the active ground cover (K_{cb cover}), which represent the transpiration component of ET_c, and a soil evaporation coefficient (K_e). The model was calibrated and validated by comparing model simulated with TDR observed soil water content data. A good fit was obtained showing that modeling was accurate when using the observed fraction of active ground cover, its density and its height, and calculating K_{cb cover} with field measured data, thus allowing to assess the active ground cover transpiration. As for the vine crop, the best fit was obtained for K_{cb full ini}=0.30, K_{cb full mid}=1.15 and K_{cb full end}=0.90.