Insights for the Partitioning of Ecosystem Evaporation and Transpiration in Short?Statured Croplands

Reducing water losses in agriculture needs a solid understanding of when evaporation (E) occur and how much is used through crop transpiration (T). Partitioning ecosystem T however challenging, even more so it comes to short-statured crops, where many standard methods lead inaccurate measurements. In this study, we combined biometeorological measurements with Soil-Plant-Atmosphere Crop (SPA-Crop) model estimate E at Swiss cropland over two seasons winter cereals. We compared our results data-driven approaches: The Transpiration Estimation Algorithm (TEA) the underlying Water Use Efficiency (uWUE). Despite large differences productivity both years, evapotranspiration (ET) ratio had relatively similar seasonal diurnal dynamics, averaged 0.72 0.73. Our SPA-Crop provided estimates TEA method, while uWUE method produced systematically lower soil leaves were dry. was strongly related leaf area index, but additionally varied due climatic conditions. most important drivers controlling found be photosynthetic photon flux density (R2 = 0.84 0.87), vapor pressure deficit 0.86 0.70). suggest that site-specific studies can help establish T/ET ratios, as well identify dominant drivers, which could then partition from reliable ET Moreover, suitable tool for partitioning croplands.