Simulation of faba bean (Vicia faba L.) growth and development under Mediterranean conditions: Model adaptation and evaluation

This study reports the adaptation of a simple and mechanistic crop growth m odel for faba bean (FAGS) to growing conditions in the Mediterranean region . The FAGS model was originally developed for small-seeded cultivars grown in the temperate zone under non-limiting water and nutrient conditions. In order to account for the effect of drought stress on faba bean growth, a su bmodel for the simulation of soil water balance has been included in the FA GS model. The enhanced FAGS model was calibrated using data from field expe riments with a large-seeded faba bean genotype (ILB 1814) conducted in 1993 -1994 and 1994-1995 at ICARDA's Tel Hadya research station in northern Syri a. In both seasons, crops were sown on two dates under different water supp ly levels. The model was capable of predicting the faba bean phenology, lea f area development, biomass production, and grain yield as well as the soil water extraction using daily climatic data, genotype-specific parameters, and soil physical properties. The calibrated faba bean model was tested aga inst independent experimental data from the 1991-1992 and 1992-1993 growing seasons at Tel Hadya and was able to satisfactorily predict grain yield of crops grown under different drought intensities. Limitations of the model and aspects requiring better understanding to improve model predictions are discussed. (C) 1998 Elsevier Science B.V. All rights reserved.