There have been few research studies on nitrogen (N) fate in turfgrass that have lasted beyond a couple years. Nitrate-nitrogen (NO₃-N) leaching in a mature Kentucky bluegrass (Poa pratensis L.) turfgrass has now been examined continuously from 1998 through 2005 at the Long-Term Nitrogen Fate Research Area at Michigan State University. The fate of nitrogen was examined for 15-year old Kentucky bluegrass turf using monolith lysimeters. From 1998 through 2003 two nitrogen rates were analyzed: 245 kg N ha^-1 (49 kg N ha^-1 application^-1) and 98 kg N ha^-1 (24.5 kg N ha^-1 application^-1). In 2004 the high N rate was reduced to 198 kg N ha^-1 (49 kg N ha^-1 application^-1). Since 1998, NO₃-N concentrations in leachate for the low N rate have typically been below 5 mg L^-1. From 2000-2003, for the high N rate, NO₃-N concentrations in leachate were often greater than 20 mg L^-1. In 2004, NO₃-N concentrations in leachate declined dramatically from previous levels to less than 10 mg L^-1. Results from 2005 are still pending. The results emphasize the importance of long-term research to investigate nutrient fate in turfgrass.