Vol. 116 (2003): Proceedings of the Florida State Horticultural Society
Ornamental, Garden & Landscape

Effect of fertilizer source on nitrate leaching and turfgrass quality

Laurie E. Trenholm
University of Florida

Published 2003-12-01

Keywords

  • best management practices,
  • nitrogen leaching,
  • turf fertilization

Abstract

Due to increasing concern over potential pollution of Florida's water resources from fertilization of home lawns, state wide research is being conducted to verify different aspects of turfgrass Best Management Practices. The objectives of this study are to evaluate differences in plant visual quality and growth responses, and fertilizer leaching between turfgrass and landscape plants in response to different fertilizer formulations. The experiment was conducted in a climate controlled greenhouse at the G. C. Horn Turfgrass Field Laboratory at the University of Florida in Gainesville. 'Floratam' St. Augustinegrass (Stenotaphrum secundatum [Walt.] Kuntze.) was compared to a mix of ornamentals including Canna ( Canna generalis), Nandina (Nandina domestica), Ligustrum ( Ligustrum japonicum) and Allamanda (Allamanda spp). All plants were grown in 303 L plastic pots in an Arredondo fine sand. There were three fertilizer treatments (16-2-7 quick-release (e.g., 16-4-8), 15-0-12 quick-release (e.g., 15-0-15), 8-2-10 slow-release (e.g., 8-4-12) applied at 4.9 g nitrogen per m every other month. Water was applied to meet the evapotranspiration and turfgrass tubs were mowed weekly. Experimental design was a randomized complete block design with four replications. Leachate was collected at three intervals following fertilizer application and analyzed for nitrate nitrogen and phosphate content. Visual quality ratings and time domain reflectometry (TDR) data were collected weekly and multispectral reflectance (MSR) readings were taken every other week. Preliminary data indicated that turf is more responsive to fertilizer treatment than ornamentals. Best turfgrass reactions were in response to quick release treatments in the first two weeks following fertilizer application.