Monday, November 13, 2006 - 9:15 AM

The Effect of Rootzone MIX and Compaction on Nitrogen Leaching in Turfgrass.

Sang-Kook Lee, Kevin, W. Frank, and James R. Crum. Michigan State University, Crop & Soil Science, Crop & Soil Science, East Lansing, MI 48823, United States of America

Research on nitrate-nitrogen (NO3-N) leaching in turfgrass indicates that in most cases leaching poses minimal risk to the environment.  Although there have been many studies investigating NO3-N leaching, there has been little research to investigate the effect of compaction level and rootzone mix on nitrogen (N) leaching.  The research objectives are to determine the effect of compaction level and rootzone mix on nitrogen leaching.  The three rootzone mixes are 69:31, 79:21, 89:11 and 96:4 % (sand: soil).  The four levels of compaction energies are 1.6, 3.0, 6.1, and 9.1 J cm-2.  Nitrogen will be applied using urea at a rate of 147 kg ha-1 split among three applications.  Rootzone will be packed into a polyvinylchloride pipe with a perforated bottom to facilitate drainage.  Rootzone depth will be 30cm over a 5cm gravel layer.  The columns will be sodded with Poa pratensis.  Hoagland solution designed for cool-season grasses, minus N, will be used to ensure adequate nutrition in the rootzone.  Turf color, quality and clipping yield will be recorded from each tube at two-week intervals.  The clippings will be oven-dried at a temperature of 67 ºC for 24 h and weighed.  At the end of the study, root dry weight will be determined by washing and oven-drying samples at 67 ºC for 24 h.  Leachate solution will be collected weekly for analysis.