@article{fdi:010074934,
  title = {{P}artitioning evapotranspiration of a drip-irrigated wheat crop : inter-comparing eddy covariance-, sap flow-, lysimeter- and {FAO}-based methods},
  author = {{R}afi, {Z}. and {M}erlin, {O}livier and {L}e {D}antec, {V}. and {K}habba, {S}. and {M}ordelet, {P}. and {E}r-{R}aki, {S}. and {A}mazirh, {A}. and {O}livera-{G}uerra, {L}. and {H}ssaine, {B}. {A}. and {S}imonneaux, {V}incent and {E}zzahar, {J}. and {F}errer, {F}.},
  editor = {},
  language = {{ENG}},
  abstract = {{A} precise estimate of the evapotranspiration ({ET}) partitioning is fundamental for determining the crop water needs and optimizing irrigation management. {T}he plant transpiration ({T}) is generally considered to be the most desirable component, while reducing the soil evaporation ({E}) could be one of the most important water-saving actions in semi-arid agricultural regions. {G}iven the lack of reference method to estimate the {E}/{T} partitioning of wheat crop, this study inter-compares four different methods based on eddy covariance, sap flow and lysimetry measurements and {FAO} modeling. {T}he objectives are: i) to quantify the systematic and random uncertainty in {E} and {T} observations, ii) to evaluate the partitioning ratio ({T}/{ET}) at the daily/field scale and iii) to assess the performance of the {FAO} model over two drip irrigated wheat fields. {R}esults indicate that despite the small surface sensed by mini-lysimeters, the partitioning ratio is evaluated more precisely (19% relative error) with lysimetry than with the other systems (any combination of eddy covariance, lysimetry and sap flow measurements). {M}oreover, stem-scale {T} measurements from sap flow sensors are subject to representativeness issues at the field scale, and to systematic errors during water-stress and senescence periods. {T}he lysimeter-derived partitioning ratio increases from about 0.50 to 0.85 during the growth stage and rapidly drops towards 0 during senescence. {I}ts dynamics is found to be significantly correlated ({R} > 0.7) with the 5-cm soil moisture. {B}y comparing {FAO} simulations with observations, it is found that the {FAO} method overestimates {T} and underestimates {E}, while keeping satisfying {ET} estimates for drip irrigated wheat. {T}his study suggests that different independent measurement techniques should be implemented to both quantify and reduce uncertainties in the {T}/{ET} ratio, and that accurate observations are still needed to improve the modeling of {E}/{T} components.},
  keywords = {{W}heat ; {E}vaporation-transpiration ; {S}ap flow ; {L}ysimeter ; {E}ddy correlation ; {FAO}-56 ; {MAROC}},
  booktitle = {},
  journal = {{A}gricultural and {F}orest {M}eteorology},
  volume = {265},
  numero = {},
  pages = {310--326},
  ISSN = {0168-1923},
  year = {2019},
  DOI = {10.1016/j.agrformet.2018.11.031},
  URL = {https://www.documentation.ird.fr/hor/fdi:010074934},
}