Comparison of Soil Moisture Uniformity In Sprinkler and Subsurface Drip Irrigated Warm Season Turfgrasses.

Subsurface drip irrigation has been shown to deliver water more efficiently than sprinkler irrigation in agricultural field crops. However, information is lacking about its efficiency on turf areas. A study was conducted at New Mexico State University during the growing seasons of 2010 and 2011 to compare irrigation uniformity of a subsurface drip (Toro DL2000) and a sprinkler system (MP Rotator 2000) used to irrigate ‘Sea Spray’ seashore paspalum and ‘Princess 77’ bermudagrass with either potable (0.7 dS m^-1) or saline (2.5 dS m^-1) water. Plots measured 20 m by 20 m and were irrigated at 80% of ETo daily and mowed at the height of 2 cm. A Time Domain Reflectometer (Fieldscout TDR300, Spectrum Technologies, Inc) was used 24 hours after irrigation events to determine volumetric water content (VWC) within the rootzone at a depth of 0 to 7.5 cm. Additionally, soil moisture was measured daily during 72 hour dry down experiments.

In 2010, the sprinkler system provided greater moisture uniformity than the subsurface drip system, and plots irrigated with saline water exhibited greater moisture uniformity than plots irrigated with potable water. At the beginning of each of the dry down periods in 2010, 'Sea Spray' plots had higher soil moisture contents but both 'Sea Spray' and 'Princess 77' had extracted the same amount of water by the end of the 72 hour dry down periods.