Sensitivity analysis of AquaCrop model for input parameters in simulating growth and yield of pearl millet (Pennisetum Glaucum L.) in semi-arid region of Nigeria

The need for a localized crop model that will aid in evaluating various strategies for efficient water management, especially in the semi-arid Lake Chad region does not need to be overemphasized. Therefore, as a step to simplify the calibration of the AquaCrop model, this study assessed the sensitivity of the model’s output variables to pearl millet crop input parameters under water stress conditions of Maiduguri, Northeastern Nigeria. The analysis was carried out using the Local Sensitivity Analysis (LSA) technique under a 50 % deficit irrigation scenario. The result revealed that the effects of the input parameters on canopy cover (CC) and biomass yield (BMY) simulations were time-dependent. Overall, a significant number of the model’s inputs were found to be non-influential; these parameters could be set within their predetermined range in order to simplify the model. Whereas, the influential parameters should be given higher consideration during calibration, data collection, and future model development. The results of this study could also be validated using more advanced methods like the Global Sensitivity Analysis (GSA) technique, on different crop varieties that have longer phenological stages and under severe water and fertility stresses.