An analytical solution considering multiple environmental variables and their effects on plant response is used to predict water use and yield of crops with variable soils, climate conditions, input irrigation water levels and irrigation water quality. Plant response to salinity is shown to be very dependent on soil hydraulic properties and somewhat dependent on climate demand and cannot simply be regarded as plant specific. Yield and transpiration decreases due to salinity of irrigation water are more severe in heavier as compared to lighter soils. Solute concentration of soil water solution is determined considering water balance and chemical-soil interactions. Evapoconcentration curves for some representative water qualities in the Colorado Basin were developed from an equilibrium chemistry computer speciation model. The curves were used to predict the relationship between salinity level and salt composition of the irrigation water and the drainage water, rather than assuming that salts are conservative. Environmental and agricultural implications of irrigation with saline water sources are demonstrated for case studies from the Western United States and Israel.