Frequent Interseeding and Nitrogen Applications to Maintain Turf Cover on Heavily Trafficked Soccer Turf.

Turf managers of northern, cool-season municipal and club soccer fields subjected to constant, heavy use are often unable to schedule reasonable periods of time for repair or renovation of worn turf. These fields often display excessive wear injury by fall or early winter. To assess the potential for ongoing management practices to produce and maintain acceptable turf cover through the playing season (and without removing a field from play), the interseeding of ‘Award’ Kentucky bluegrass (Poa pratensis L.) or ‘SR4600’ perennial ryegrass (Lolium perenne L.), at 2- or 4-week intervals from May through September, was evaluated on a native soil bluegrass soccer field (silty-clay-loam) in Fort Collins (CO). Seeding was done with or without fertilizer applications, using a 24-4-16 fertilizer; nitrogen was applied at a rate of 24.4 or 48.8 kg/ha. In 2007, biweekly and monthly fertilizer application significantly increased both color and turf density ratings from June through November. Neither bluegrass nor ryegrass overseeding significantly affected turf quality or density in 2007 (applied with or without fertilizer), although small seedlings were present (for both species) in overseeded plots at all observation dates. First-year results suggest that monthly or biweekly N fertilization may be more effective for maintaining acceptable turf quality and density than overseeding, at least in the short-term. Fertility and seeding treatments will be continued in 2008 to assess cumulative effects of both management practices on quality, density, and ability to resist and/or recover from soccer traffic.