Total Nitrogen Losses from Fertilized Turfs on Simulated Highway Slopes in Florida

Abstract

AbstractFertilized highway slopes constitute nonpoint sources of nitrogenous nutrients that are degrading the surface water and groundwater resources. This paper presents the results of simulated rainfall experiments conducted on a plot-scale test bed (slope-adjustable) that was fully exposed to weather for closely representing the conditions of a fertilized turf-covered highway slope in Florida. Thirty-six tests were conducted on three slopes (25, 33, and 50%), simulating two rainfall intensities (12.5 and 25 mm/h). The soils used were fine sand (AASHTO A-3 class) and silty sand (AASHTO A-2-4 class). Following the local highway practices, the tests were conducted after compacting the soils and establishing Argentine Bahia turf over A-3 soils and Pensacola Bahia turf over A-2-4 soils. Two fertilizers were used: a quick release (QR) 10-10-10 and a slow release (SR) 16-0-8. Weather conditions varied considerably during the duration of the project, affecting soil moisture, soil—grass—nutrient interactions, ...