A micrometeorological approach based on the surface energy balance was adopted to estimate evapotranspiration fluxes and cropcoefficient data from an irrigated cactus pear [Opuntia ficus-indica L. (Mill.)] orchard under Mediterranean climatic conditions. Highfrequencytemperature readings were taken above the canopy top to get sensible heat flux values (HSR) using the surface renewal technique.These values were compared against eddy covariance sensible heat fluxes (HEC) for calibration. Latent heat flux (or evapotranspiration, ET)was obtained by solving the daily energy balance equation. Measurements of soil hydraulic components were integrated with the analysis ofthe surface energy fluxes and crop development in terms of phenology and aboveground biomass accumulation. Microlysimeters were used tocompute evaporation rates, allowing the separation of daily transpiration from ET data. Ecophysiological measurements were carried toestimate dry weight accumulation and partitioning. Cactus pear evapotranspired a total of approximately 286 and 252 mm of water duringthe two monitored growing seasons, respectively. Average daily values of crop (ETc) and reference (ET0) evapotranspiration were in the orderof 2.5 and 5.0 mm, respectively, with a corresponding value of the mean crop coefficient of approximately 0.40. The annual dry mass fixed persingle tree was 38.8 1.3 kg, with a total production of 12.9 t ha−1, which is comparable to many C3 and C4 plants and resulted in a wateruse efficiency (WUE) of 4.6 and 4.4 gDMkgH2O−1 in 2009 and 2010, respectively. The stem area index (SAI) was 3.5.
|Numero di pagine||11|
|Rivista||JOURNAL OF IRRIGATION AND DRAINAGE ENGINEERING|
|Stato di pubblicazione||Published - 2013|
All Science Journal Classification (ASJC) codes
- Civil and Structural Engineering
- Water Science and Technology
- Agricultural and Biological Sciences (miscellaneous)