Soil salinity is a major factor impacting the productivity of irrigated agricultural lands in arid and semi-arid regions. In these areas, irrigation is necessary for producing most crops. With climate change affecting the snowpack and freshwater supplies in arid and semi-arid regions, it is important to understand the ways that water scarcity can affect agricultural production. This study demonstrates the interaction between salinity and water availability as one such mechanism. Specifically, using a novel interdisciplinary approach, we study agricultural producers' crop choices in response to soil salinity and winter snowpack, which provides a signal regarding water availability and salinity during the growing season. The analysis considers the agronomic effects of increased salinity on crop yields, as well as the behavioral response of producers to higher soil salinity and water availability through crop and land use choices. We show that an increase in root zone salinity increases the probability of a parcel being fallowed, decreases the probability of parcels being irrigated, and decreases the probability of high-value crops such as corn being planted. A decrease in winter snowpack can compound this effect and increase the effect of salinity on fallow acres. We estimate the cost of a 50% increase in soil salinity to be $36 (9%) per acer on average, with even higher costs in years where surface water availability is lower.