Agronomic-Economic Coupled Decision Support Application for Irrigation with Water Containing Salts.

We present a biological-physical model of water and salt balance, plant water use and plant response to stress (ANSWER model, Shani et al. 2007, Water Resour Res) coupled with economic calculations for profit in order to consider options for irrigating with water of varied salinity. The coupled model is packaged in a user-friendly menu- and web-based platform. Model inputs characterize the physical (soil hydraulic properties, weather), biological (crop relative response functions to water and salt), management (applied water quality and quantity), and economic (yield value, yield determined and static expenses, capital return, water pricing, farm unit size, etc.) parameters. The application returns yield and profit data for any scenario and allows consideration of environmental repercussions of economic decisions through calculation of leachate carrying excess water and salts out of the root zone.  To demonstrate the potential of the application, we bring a case study for evaluation of desalination for irrigation of crops in Israel.