Analyzing the effect of environmental conditions on vineyard eco-systemic water use efficiency under semi-arid field conditions

Water use efficiency (WUE) at ecosystem level (WUE_EC) can be expressed through the ratio between net ecosystem CO₂ exchange (NEE) and evapotranspiration (ET). The fact that WUE at leaf scale depends on changes in atmospheric demand or daily pattern of leaf exposure to the sun, it exhibits high variation within the canopy and does not allow an adequate characterization of WUE under field conditions.
At canopy level WUE_EC also depends on atmospheric demand conditions or daily patterns of light absorption.
The quantification of water vapor and CO₂ fluxes in a whole plant or orchard ecosystem allows generating more comprehensive and realistic values of WUE under agricultural field conditions.
This work aims to contribute to the analysis of WUE_EC in vineyard orchard ecosystems.
For this purpose we analyze the changes in CO₂ fluxes and water vapor fluxes (ET) and WUE_EC in irrigated and rain-fed vineyards, with high differences in irrigation management, soil humidity content and meteorological conditions.
Our results indicate that the effects of the atmospheric conditions are superimposed to the effect of water availability on WUE_EC. For this reason, it is necessary to analyze deeper the dependency of WUE on atmospheric demand and its influence in the agronomic management of irrigation.

VIII International Symposium on Irrigation of Horticultural Crops

C. Balbontín, I. Campos, N. Franck, A. Calera

water use efficiency, vineyard, eddy covariance, gross primary production, net assimilation

https://doi.org/10.17660/ActaHortic.2017.1150.13