Modeling malt barley water use and evapotranspiration partitioning in two contrasting rainfall years. Assessing AquaCrop and SIMDualKc models

• Published in: Agricultural water management 2015-09, Vol.159, p.239-254
• Main Authors: Pereira, Luis S., Paredes, Paula, Rodrigues, Gonçalo C., Neves, Manuela
• Format: Article
• Language: English
• Subjects: Canopy cover; Crop transpiration; Dual crop coefficient; Fraction of ground cover; Hordeum vulgare; Soil evaporation; Soil water balance
• ISSN: 0378-3774; 1873-2283
• DOI: 10.1016/j.agwat.2015.06.006

•SIMDualKc and AquaCrop hydrologic approaches were assessed for contrasting rainfall years.•SIMDualKc simulated soil water accurately after partitioning ET with the FAO dual Kc approach.•AquaCrop uses an empirical approach for ET partition depending on the canopy cover.•AquaCrop showed insufficiencies in soil water simulation and in transpiration and soil evaporation estimation.•Differences in models’ approaches to compute the water balance terms are discussed. Two contrasting rainfall barley seasons, dry (2012) and wet (2013), were used to parameterize and assess the performance of the SIMDualKc and AquaCrop models. Field data were obtained from malt barley cropped in a farmer’s field in Ribatejo, Portugal. SIMDualKc applies the dual crop coefficient approach for computing and partitioning crop evapotranspiration (ET), while AquaCrop uses an empirical approach to estimate potential crop transpiration (Tc) and soil evaporation (Es) depending upon the canopy cover (CC). The calibration and validation of both models was performed through comparing observed and predicted soil water content (SWC) for both seasons. The goodness-of-fit indicators were very good for SIMDualKc, with low errors of estimate (RMSE