Impact of Annual Nitrogen Rate and Mowing Height On Thatch Development of 'TifBlair' Centipedegrass (Eremochloa ophiuroides).

Centipedegrass (Eremochloa ophiuroides) is a commonly used home lawn turfgrass species in the southern and southeastern USA.  Relative to other warm-season turfgrasses, it is maintained with lower annual nitrogen fertility and management inputs to produce an acceptable turfgrass sward.  In 2003, a study to investigate the long-term interactions of various nitrogen rates and mowing heights was initiated at two locations in Georgia, Griffin and Tifton.  The studies were established in existing stands of ‘TifBlair’ centipedegrass and plots were treated the same for each location during the three subsequent years.  Mowing heights of 3.8 and 7.6 cm were maintained and fertilized with six nitrogen rates either as a single application in May (24.5, 49.0, 98.0 kg ha^-1) or sequential applications in May and August (24.5 + 24.5, 49.0 + 49.0, and 98.0 + 98.0 kg ha^-1).  A seventh treatment of 24.5 kg ha^-1 was applied four times in March, May, July and August.  A nontreated control was also included where no nitrogen was applied for four years.  Following spring transition, two samples were removed from each plot to determine organic matter accumulation by loss on ignition (LOI).  In regards to spring green-up and overall turfgrass quality, plots with an annual nitrogen application rate of 49.0 kg ha^-1 and mowed at 3.8 cm were superior to other treatments.  Similarly, nitrogen rate and mowing height affected organic matter accumulation with the higher mowing height and nitrogen rates increasing organic matter accumulation over the four year sampling period.