Understanding the interaction between groundwater salinity and irrigation decision making has important implications for groundwater management. Econometrics models were estimated using observed farmer behavior in response to different groundwater salinity levels in a region of Kansas. Estimation results demonstrate that farmers in the face of groundwater salinity change their irrigation decisions on irrigated acreage (i.e., extensive margin), crop choice (i.e., indirect intensive margin), and water application depth (i.e., direct intensive margin). The empirical results indicate an overall decrease in water use due to higher salinity, primarily through a decrease at the extensive margin.