Calibration and evaluation of aqua crop model in rice growth simulation under different irrigation managements

Abstract

Due to the growing population and demand of food, increasing water productivity holds the key to future water scarcity and food security challenges. To achieve this, a good understanding of crop response to water stress and tools which simplify the complex crop response to various environmental factors, especially to water, are needed. FAO recently developed a water-driven model (AquaCrop) for use as a decision support tool in planning and scenario analysis in different seasons and locations. In this study, the Aquacrop model was calibrated and evaluated for a lowland local rice cultivar (Champa-Kamfiroozi) in the Kooshkak area (semi-arid climate), Fars province, Iran, with data from an experiment with five irrigation treatments in two consecutive years. According in this study, the model efficiency (ME) for canopy cover simulation was 0.34 to 0.82. The simulated grain yield deviated from the observed data with a range of 0.1% to 7.8% in 2000 and -19% to 0.2% in 2001. The model efficiency (ME) for grain yield simulation in 2000 and 2001 were 0.98 and 0.5, respectively. The root mean square error (RMSE) for grain yield simulation in 2000 and 2001 were 0.09 and 0.7 t ha-1, respectively. The AquaCrop model can adequately simulate the canopy cover development and grain yield of rice under different irrigation managements. The model can be used to explore management options to improve rice water productivity