Evaluation of Aquacrop model for a potato crop under different irrigation conditions

The processes of calibration and validation of the Aquacrop model for the simulation of the growth and development of a potato crop (Agria cultivar) that was irrigated with a center pivot system are described in this study. The field experiments were conducted during 2011 (calibration) and 2012 (validation) in a semiarid region in southeastern Spain. The potatoes were irrigated with four treatments (120%, 100%, 80%, and 60% of the water requirement). The Aquacrop model was suitable for the simulation of the growth and development of potatoes in the climatic conditions of the study area. The canopy cover, total dry matter, dry matter of tubers and evapotranspiration were the primary variables analyzed. An acceptable goodness of fit was found between observed and simulated values. So, statistical indicators such as the Willmott index of agreement (d) and the coefficient of determination (R-2) showed good values (d and R-2 > 0.90) for the primary variables analyzed. Both the model and the observed data found that 80% and 60% of the water requirements were the treatments that were most efficient in the use of water. A high temperature stress coefficient affecting the harvest index is recommended to be incorporated in the model for avoiding overestimations of yield. (C) 2015 Elsevier B.V. All rights reserved.