Nitrogen Required for Acceptable Centipedegrass Quality, Color, Growth Rate and Nitrate Leaching

In north Florida, nitrogen (N) application recommendations for centipedegrass [Eremochloa ophiuroides (Munro) Hack.] range from 49 to 98 kg N ha^-1 yr^-1.  The objective of this study was to determine the minimum amount of N necessary to produce acceptable quality centipedegrass while also measuring the influence of N rate and irrigation rate on color, growth rate, and NO₃-N leaching.  Nitrogen was applied at rates of 18, 36, 74, and 147 kg N ha^-1 yr^-1 split evenly into three applications to common centipedegrass. Acceptable quality was produced by N applied at 18 kg N ha^-1 yr^-1 during most cycles but not all.  Regression models indicated annual average quality may result without applying N.  Color was similar to quality with acceptable color observed from N applied at 18 kg ha^-1 yr^-1 and increasing with increasing N rates.  Nitrate-N leaching was equivalent for N rates 18 and 147 kg ha^-1 yr^-1.  However, when N rates increased from 18 kg ha^-1 yr^-1 to 36 and 74 kg ha^-1 yr^-1, annual NO₃-N leaching was reduced by approximately 50%.  Current recommended N rates may be more than is necessary to produce acceptable quality centipedegrass; however, the rates do not pose an increased risk to NO₃-N leaching.