Rootzone Characteristics and Bermudagrass Response to Saline Water Applied by Subsurface Drip Irrigation at Two Irrigation Volumes.

Escalating population growth and recurring droughts in the Southeastern US have placed high demands on the limited supplies of freshwater. Using valuable freshwater for turfgrass irrigation has been scrutinized in the past, thus alternative irrigation methods and practices are needed to maintain turfgrass.  A combination of using a lower quality water source applied at reduced irrigation volumes with a subsurface drip irrigation system has been documented as an effective strategy for water conservation in the Southwest US.  There may be more potential for this practice in the Southeast due to the humid climate and frequent rainfall. An experiment was conducted to investigate ‘Tifway’ bermudagrass (Cynodon dactylon (L.) Pers. X C. transvaalensis Burtt Davy) quality, growth, and root-zone characteristics when applying saline (3.15 dS m^-1) and freshwater (0.07 dS m^-1) by a subsurface drip irrigation system at two irrigation volumes to equal either 65 or 100% predicted evapotranspiration (ETp) .  A field-scale facility was constructed and two experiments were performed for eight weeks during high peak water demand periods in the summer months of 2007 and 2008 at Clemson University’s Pee Dee Research and Education Center in Florence, SC.  Bermudagrass growth, as measured by clipping yields, stolon density and root mass, were not influenced by water source or irrigation volume for either experiment. During the severe drought summer (2007), soil electrical conductivity increased with depth and was influenced by both factors. In comparison, during the 2008 summer when rainfall abundance was similar to the 2004-2006 average, neither factor influenced soil electrical conductivity. Minimal differences in visual quality were determined for both years. This study documented that quality bermudagrass can be maintained when irrigated with saline water at an irrigation volume less than 100 % ETp.