Bermudagrass Response to Saline Water Delivered by a Subsurface Drip Irrigation System.

Population increase and recurring drought conditions have placed high demands on potable water resources in South Carolina. Thus turfgrass irrigation has become under scrutiny and proper management of alternative water sources and delivery methods for maintaining quality turfgrass need to be identified. Previous research documents water conservation for bermudagrass management by using saline water sources and subsurface drip irrigation (SDI) systems. However the research has been primarily conducted in the Southwest USA where arid conditions persist and rainfall is minimal. A field-scale facility was constructed at Clemson University’s Pee Dee Research and Education Center in Florence, SC, to evaluate ‘Tifway’ bermudagrass quality, growth, and rootzone characteristics to saline (3.19 dS m-1) and freshwater (0.08 dS m-1) irrigation, SDI line spacing (41 or 81 cm), and two irrigation rates (65 or 100% ETp). Two, 8-week experiments were conducted during peak freshwater use and high evapotranspiration (ET) demand periods in 2007 and 2008. Visual quality was observed weekly and growth assessed by clipping yields, stolon counts, and root mass determinations. Soil electrical conductivity (EC) was assessed at 0-10, 10-20 and 20-30 cm depths at pre, mid, and post trial intervals. During Week 5 of the 2007 experiment, 100% ETp freshwater irrigated bermudagrass with the narrow SDI line spacing had greater quality than bermudagrass with the wider SDI line spacing (P=0.0635). Post experiment shoot density and root mass from saline irrigated plots were greater than freshwater irrigated plots. Mid and post-experiment soil EC were higher from saline water irrigated bermudagrass than freshwater irrigated bermudagrass. There was minimal influence on soil EC from ET and Spacing factors, and only for post-experiment measurements. Our results suggest that saline water can be applied during periods of high potable water demand to maintain quality bermudagrass.