Global sensitivity analysis of crop yield and transpiration from the FAO-AquaCrop model for dryland environments

The application of crop models towards improved local scale prediction and precision management requires the identification description major factors influencing model performance. Such efforts are particularly important for dryland areas which face rapid population growth increasing constraints on water supplies. In this study, a global sensitivity analysis yield transpiration was performed 49 parameters in FAO-AquaCrop (version 6.0) across three farming with different climatic conditions. Morris screening method variance-based Extended Fourier Amplitude Sensitivity Test (EFAST) were used to evaluate parameter sensitivities several staple crops (maize, soybean or winter wheat) under dry, normal wet scenarios. Results suggest that vary target output (e.g., yield, transpiration) wetness condition. By synthesizing scenarios, key affecting performance both high low stress identified crops. Overall, relevant root development tended have large impacts stress, while those controlling maximum canopy cover senescence more influential stress. Parameter also shown be stage-dependent from day-by-day biomass simulations. Subsequent comparison AquaCrop version 5.0 suggests 6.0 is less sensitive uncertainties soil properties.