Mowing System and Overseeding Rates On Kentucky Bluegrass American Football Fields.

Mowing height and overseeding rate is known to impact turfgrass health, density, rooting depth, and long-term stand viability, but little is known regarding the combined effects on American football fields. The objectives of this study are to determine the combined effects of mowing height and overseeding rates on Kentucky bluegrass. Seven overseeding rates (fall applied at 0, 4.5, 9, 18, 36, 72, or 144 kg ha^-1) and two mowing height management systems were evaluated in all combinations with three replications in a strip-plot design. Continual low mowing height was at 3.2 cm year round and the adjusted mowing height was at this same level from six weeks prior (July 20) to the first home game through the spring exhibition game (April 5), with mowing height of 5.1 cm in the off-season. For the adjusted mowing height treatments, the transition between mowing heights in the late summer was managed by gradually lowering the height over six weeks to avoid scalping. Mowing management system did not influence any measured parameter during the first year of study. The highest seeding rate negatively influenced verdure. There was a significant linear increase in rooting depth peaking at a 19% increase with the 36 kg ha^-1 rate, but then dropped back to below the control at the two highest seeding rates. Crown density also increased linearly through the 36 kg ha^-1 rate (153% increase) and then increased exponentially to 447 and 553% for the highest two seeding rates due to weak plants not being able to out compete one another to the point of exclusion of the weakest plants. Additional research is needed to evaluate the long-term impacts of mowing and seeding rates on athletic fields.