Evaluating Supina Bluegrass As a Companion Species for Overseeding Athletic Fields.

Athletic fields are under a tremendous amount of traffic stress during the growing season. Overseeding with perennial ryegrass (PR) is used to remediate this problem although it can lead to weaker stands the following season because of its limited winter hardiness.  An evaluation of supina bluegrass (SB) as a companion to overseeding with PR was performed at varying rates, frequencies and mowing heights. In addition to a non-overseeded check treatments were overseeded with 6 kg 100 m^-2 year^-1 PR, in conjunction with SB at 0 kg 100 m^-2 year^-1, 0.5 kg 100 m^-2 year^-1, 1 kg 100 m^-2 year^-1, 2 kg 100 m^-2 year^-1, and 4 kg 100 m^-2 year^-1.  Plots were either seeded one time or seeded at one third the yearly rate three times throughout the growing season.  Turfgrass sward composition was measured using point quadrats, and soil samples were taken in the fall and spring to determine the effects of overseeding on the composition of the seedbank. The data demonstrated that within overseeding rate, the plots overseeded three times a season have greater turfgrass coverage than plots overseeded once.  Supina bluegrass overseeding resulted in SB being the dominant species in the seedbank with a positive correlation to seeding rate. Interestingly, the higher seeding rates of SB resulted in more PR seed in the seedbank. The research thus far shows that SB may be a viable overseeding option for athletic fields.