The effect of shallow, saline water tables on the irrigation requireme
nts of corn, alfalfa, and winter wheat was determined using lysimeters
in western Colorado. The crops were grown with no water table and wit
h water-table depths of 0.60 and 1.05 m supplied with water having ele
ctrical conductivities of 0.66, 3.0, and 6.0 dS/m. The portion of tota
l seasonal evapotranspiration supplied from shallow groundwater was st
rongly affected by water-table depth and, for corn and wheat, slightly
affected by salinity of the water in the saturated zone. Results sugg
est that surface irrigations may be reduced when shallow water tables
are present.