Nitrogen based establishment and seedbanking potential of Kentucky bluegrass and perennial ryegrass in athletic fields

This dissertation outlines work done that investigated the potential of perennial ryegrass and Kentucky bluegrass to form useful, transient seedbanks in athletic field scenarios as well as speeding both spring and fall establishment of said species with increased nitrogen rates. Under the conditions of the studies, neither Kentucky bluegrass nor perennial ryegrass exhibited long term viability, i.e. seedbanking potential, when seeded to bare ground at three different seeding rates and two seeding schedules (one time vs. multiple). Seed was exhausted in the single seeding schedule as most seed germinated and little was left over to germinate later in the season or beyond. In the multiple seeding schedule, seed was available for germination later in the season and at the end of the traffic period, but did not carry over into the following year. It appeared that a true seedbank was not being formed; rather, multiple inputs were responsible for providing a source of fresh seed available for germination in the season of planting only. Turf managers would benefit from a single, early seeding followed by multiple overseeding events to provide germinable seed through the season. Increased nitrogen rates during establishment appeared to provide better color and cover for both species when used with normal seeding rates. Increasing both seeding rate and nitrogen level masked the effects of nitrogen. Further, increasing nitrogen rates beyond historically established norms during establishment did not reduce the traffic tolerance of either species