Nitrogen Source and Rate Effects on ‘Seadwarf' Seashore Paspalum Putting Green Establishment with Two Sprigging Rates.

Turf managers in coastal areas are having to manage turfgrass with increasingly poor water quality and on water restrictions.  Seashore paspalum (Paspalum vaginatum Swartz.) may offer a solution for many since it is known to tolerate poor water quality including irrigating with sea water.  However, information on Seashore paspalum used as a putting green in inland areas is lacking. The objective of the study was to test the establishment efficiency of a ‘Seadwarf’ Seashore paspalum putting green with two sprigging rates, three nitrogen (N) sources, and two N rates in the inland transition zone. A study was conducted as a split block design with three replications at Clemson University in Clemson, South Carolina. Seadwarf was sprigged either at 91 m³ ha^-1 or 182 m³ ha^-1 on May 17, 2007. Urea, ammonium nitrate, and ammonium sulfate were applied at 22 or 44 kg N ha^-1 week^-1.  These N sources were soluble dissolved in water and applied as a liquid weekly for 10 weeks with a CO₂ backpack sprayer followed by a light irrigation with an estimation of 10 to 15 mm to reduce potential of foliar burns.  Potassium and phosphorus were applied as 19-19-19 at 49 kg N ha^-1 yr^-1 prior the establishment and additional applications of K and P as liquid forms at 49 kg K ha^-1 yr^-1 and 24.5 kg P ha^-1 yr^-1, respectively in week 6 after sprigging. The mowing height was gradually lowered to 32 mm in late July and 25 mm in early August with a daily mowing frequency. Weekly measurements included percent coverage and visual quality and color ratings. Samples to determine root mass were collected eight weeks and 16 weeks after sprigging.   A significant difference occurred in coverage between high and low sprig rates. The high sprig rate reached 100% coverage and acceptable turf quality within 5 weeks in comparison with the lower rate which did not occur until 7 weeks. High rates of fertility associated with high rates of sprigs produced the best quality and color ratings (greater than 7 consistently for both ratings). Ball speed greater than 3.1 meters was found with the lower mowing height of 25 mm by using a standard stimpmeter.