105-38 Influence of Nitrogen Source and Timing On Nitrate-N Leaching When Applied to Centipedegrass and St. Augustinegrass.

Poster Number 714

See more from this Division: C05 Turfgrass Science
See more from this Session: Environment, Thatch, Soil, Water and Pest Management Graduate Student Competition
Monday, October 22, 2012
Duke Energy Convention Center, Exhibit Hall AB, Level 1
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J. Bryan Unruh, Univ. of Florida, Jay, FL, Laurie Trenholm, University of Florida, Gainesville, FL, Phil Moon, University of Florida - West Florida Research and Education Center, Jay, FL and Jerry Sartain, Soil and Water Science, University of Florida, Gainesville, FL

Centipedegrass (Eremochloa ophiuroides [Munro] Hack) and St. Augustinegrass (Stenotaphrum secundatum [Walt.] Kuntze.) were established as sod at the University of Florida, West Florida REC in 2008. Over four growing seasons (2008-11), six nitrogen (N) sources were applied at 49.0 kg N ha-1 every 60 days to both species. Sources included: 1.) ammonium nitrate; 2.) urea; 3.) 30% Slow Release Nitrogen (SRN) 16-0-8; 4.) 50% SRN (19-0-19); 5.) Polymer Coated Urea (PCU) (41-0-0); and 7.) Organic biosolid (6-2-0). For comparison purposes, a 98.0 kg N ha-1 PCU treatment also was applied every 120 days to both species. An untreated control was included. Each plot contained a lysimeter with a surface area of 0.22 m2. Leachate collection was conducted weekly. Data collection included total NO-3-N leached and turf quality, color, and density. Soluble N sources yielded rapid improvements in green-up and turf quality following each application. Throughout the study, centipedegrass exhibited better turf quality, color, and density than St. Augustinegrass. Centipedegrass generally produced 8 10 times the quantity of shoots and ~30% more roots compared to St. Augustinegrass. Nutrient import with the sod negated treatment differences in the inaugural year. Over the 49 week study period (21 Apr 2009 30 Mar 2010), centipedegrass leached 67% less N than St. Augustinegrass (1.86 vs. 5.65 kg N ha-1). The winter of 2009/2010 was colder than normal resulting in significant deterioration of the St. Augustinegrass. The 49 week (20 Apr 2010 29 Mar 2011) leaching total was 23.16 kg N ha-1 for St. Augustinegrass and 1.27 kg N ha-1 for centipedegrass.

See more from this Division: C05 Turfgrass Science
See more from this Session: Environment, Thatch, Soil, Water and Pest Management Graduate Student Competition