Nitrogen fertilizer form and associated nitrate leaching from cool-season lawn turf.
Various N fertilizer sources are available for lawn turf. Few field studies, however, have determined the losses of nitrate (NO(3)-N) from lawns receiving different formulations of N fertilizers. The objectives of this study were to determine the differences in NO(3)-N leaching losses among various N fertilizer sources and to ascertain when losses were most likely to occur. The field experiment was set out in a completely random design on a turf typical of the lawns in southern New England. Treatments consisted of four fertilizer sources with fast- and slow-release N formulations: (i) ammonium nitrate (AN), (ii) polymer-coated sulfur-coated urea (PCSCU), (iii) organic product, and (iv) a nonfertilized control. The experiment was conducted across three years and fertilized to supply a total of 147 kg N ha(-1) yr(-1). Percolate was collected with zero-tension lysimeters. Flow-weighted NO(3)-N concentrations were 4.6, 0.57, 0.31, and 0.18 mg L(-1) for AN, PCSCU, organic, and the control, respectively. After correcting for control losses, average annual NO(3)-N leaching losses as a percentage of N applied were 16.8% for AN, 1.7% for PCSCU, and 0.6% for organic. Results indicate that NO(3)-N leaching losses from lawn turf in southern New England occur primarily during the late fall through the early spring. To reduce the threat of NO(3)-N leaching losses, lawn turf fertilizers should be formulated with a larger percentage of slow-release N than soluble N.
Guillard
Karl
K
Department of Plant Science Unit 4067, University of Connecticut, 1376 Storrs Road, Storrs, CT 06269-4067, USA. karl.guillard@uconn.edu
Kopp
Kelly L
KL
D005308:Fertilizers; D009566:Nitrates / Q000032:analysis / Q000737:chemistry*; D009584:Nitrogen / Q000032:analysis* / Q000737:chemistry; D006109:Poaceae; D012621:Seasons; D012995:Solubility; D014873:Water Pollutants / Q000032:analysis
D005308:Fertilizers; D009566:Nitrates; D014873:Water Pollutants; D009584:Nitrogen