Nitrogen Regime Influence on Nutrient and Sediment Surface Runoff During Vegetative Establishment of Bermudagrass
Bermudagrass (Cynodon dactylon (L.) Pers.) is a popular turfgrass used throughout the Southeast. Bermudagrass is established primarily as sprigs on large acreage sites. Currently, the industry standard practice (ISP) of fertilization during
bermudagrass sprig establishment is 48.8 kg N ha-1 wk-1. This fertilizer rate can be excessive on morphologically immature sprigs in the initial weeks of establishment, thus making the possibility of offsite surface runoff N events more likely. Two experiments were conducted in 2000 and 2001 where sprigs were established at 2, 4, 6, 8, and 10 weeks prior to applying simulated rainfall (WPRS) following N fertilization rates of the ISP or a lower initial N (LIN) rate of 12.2 kg N ha-1 wk-1 the first four weeks and then
48.8 kg N ha-1 wk-1 until full establishment. At the tenth week all treatments were subjected to rainfall simulation at 63.5 mm hr-1. Once surface runoff was induced, rainfall continued for thirty minutes during which time runoff samples were taken every five minutes and analyzed for sediment losses, N concentrations in the nitrate and ammonium forms, and phosphorus losses as dissolved reactive P (DRP). Experimental results indicate an ability to curb N losses through surface runoff during the initial weeks of sprig establishment following the LIN with only modest delays in sprig establishment.
Sprigs established for the same time period, under the ISP or LIN, were very similar in
growth, release of surface runoff, and sediment losses during runoff events.
Advisor:David R. Chalmers; Raymond Reaneau; Greg Mullins; Erik Ervin
School:Virginia Polytechnic Institute and State University
School Location:USA - Virginia
Source Type:Master's Thesis
Keywords:crop and soil environmental sciences
Date of Publication:05/07/2002