Water uptake of apple trees in the Alps: Where does irrigation water go?

Understanding root water uptake sources in agricultural systems is becoming increasingly important the sustainable management of resources under changing climatic conditions. In this work, a stable isotope approach was adopted to investigate accessed by apple trees two orchards growing different locations upper Etsch/Adige valley (Eastern Italian Alps). We tested general hypothesis that soil water, composed mixture rain and irrigation main source for tree transpiration both fields, but could also access groundwater according proximity table orchards. Our results revealed during 2015 2016 seasons relied mostly on present 20–40 cm soils, with an apparently negligible contribution groundwater, irrespective field location bottom. The isotopic composition xylem did not reflect (or groundwater) rather rainfall throughfall, water. related behaviour intense rate evaporation period modified original signature shallower layers, masking its actual contribution. This work contributes improving understanding strategies Alpine paves way further analysis proportion rainwater used mountain agroecosystems.