Divot Resistance of Thick Cut Sod as Influenced by Preharvest Nitrogen and Sand Topdressing

Professional sports facilities in the United States install thick‐cut sod during the playing season. Field performance immediately after installation is primarily determined by maintenance practices at the sod farm. This research investigated the influence of six N programs (98–245 kg N ha −1 yr −1 applied in spring or fall) and two sand‐topdressing rates (0 and 8.5 kg m −2 yr −1 ) on Kentucky bluegrass (KBG, Poa pratensis L.). In 2013 and 2014, KBG was established from seed in September and grown for 7 mo at a commercial sod farm (Hammonton, NJ) and then transported as sod and grown for another 7 mo under six by two treatment combinations at University Park, PA. Sod was harvested 14 mo after seeding and evaluated for divot resistance, shear, and sod strength. In 2013, all N treatments were similar in divot resistance except the 245‐kg total N rate, which exhibited the lowest divot resistance. In 2014, the most divot resistance was observed with 49 kg N ha −1 applied three times in the spring (147 kg total N) or using the same N program with another 49 kg ha −1 applied in September (196 kg total N). Nitrogen treatments resulted in few meaningful differences in shear resistance. Sand topdressing affected divot and shear resistance differently. Topdressing reduced divot resistance by only 6% in 2014 and had no effect in 2013. Topdressing reduced shear resistance by averages of 21.6 and 28.4% in 2013 and 2014, respectively. Growers may improve the divot resistance of KBG sod by moderating N inputs.