The 40-year-old turf course at Del Mar in Southern California has been renovated at a cost of $125,000, track officials said Wednesday. Ten of Del Mar's 27 stakes are run on the grass.The renovation, which included the planting of an acre of new sod in the homestretch, marked the first extensive repair of the course since the turns were banked in 1986. The course is named the Jimmy Durante Turf Course in honor of the entertainer who was a regular at the track for many years.Turf authority Leif Dickinson went to Del Mar last October to oversee the project. Dickinson, who is the turf and grounds supervisor at Santa Anita, also works on the turf course at Golden Gate Fields and has served as supervisor or consultant on turf courses around the country.An acre of sod was removed from the area in the stretch from the turf chute to midway on the first turn. The exposed area was covered with turf grids designed to give stability to the soil under the grass. Finally, new sod -- Kikuyu grass -- was put down. Following the sod removal and replacement, the entire turf course was seeded with Kikuyu seed and topped with a mixture of soil and turf grids.Del Mar maintenancecrews also fine-tuned the track's new irrigation system.