Developing Modified Conceptual Model for Plants Response to Simultaneous Salinity and Water Stress

In arid and semi-arid regions in addition to water quality, water quantity also limits agricultural production development. In this situation, plant is put under simultaneous water and salinity stress conditions. Modeling agronomical plant response to simultaneous water and salinity stress can help operation management of the country's limited water resources. The objective of this study was to model agronomical plant response to simultaneous water and salinity stress. To do so, first the important water uptake reduction functions are investigated using basil greenhouse data. The results of these investigations indicated that there are no relationships between matric potential at readily available water (h3) and osmotic potential in any mathematical models. In this paper, a new mathematical model for investigating agronomical plant response to simultaneous water and salinity stress is given by modifying conceptual model of Homaee et al., at h3 arm (branch). The results of evaluating this new model using basil observed data, indicated that model is able to simulate plant response to salinity stress, water stress, and simultaneous water and salinity stress very accurately (RMSE=8.5% and R2=0.97).