Evapotranspiration and soil water dynamics of peach trees under water deficits

摘要: Abstract Among the factors influencing decision-making process in irrigation, threshold level of available soil water content (AWC) is critical for irrigation timing. An experiment was conducted with mature peach trees ( Prunus persica L. Bastch) using a large weighing lysimeter to establish levels AWC evapotranspiration (ET), leaf conductance and photosynthesis during deficit period. Three approaches were used determine it found, via continuous monitoring capacitance sensors, that had not fully explored lysimeter. The onset ET decline 60 53% when calculated as difference between field capacity wilting point layer by roots (90 cm) total extracted tree from lysimeter, respectively. When whole depth (160 cm) considered reservoir uptake, started at 94% AWC; value so high suggest erroneous assumptions. Similar values found reduction photosynthesis. Soil gave diurnal patterns extraction lagged behind transpiration about 2 h morning ended earlier afternoon. Also, measured peak rates near emitters several times higher than those representing weight loss. outside watered same regime differed considerable occurred 90 180 cm. different responses demonstrate importance considering wetting patterns, depth, root exploration frequency management.