Submitted to: Grassland International Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/25/1997
Publication Date: N/A
Citation: N/A Interpretive Summary: Not required.
Technical Abstract: While intensive grazing has the potential to increase dairy farm profitability in the Northeast United States, the uneven distribution of N through feces and urine can increase NO3- leaching. We measured NO3- leaching loss from urine and feces beneath N-fertilized orchardgrass using 60 cm diameter by 90 cm deep drainage lysimeters. Mean NO3-N levels in leachate beneath these areas were 3.8, 6.5, 93.5, 110, and 139 mg l-1 for the control, feces, and spring, summer, and fall applied urine. Extrapolation of this leaching data over a grazed landscape indicates that a grazing intensity for a 180-day grazing season on the order of 240 animal (mature Holstein cow) days (AD) ha-1 yr-1 can result in a leachate of 10 mg l-1 of NO3-N (the U.S. EPA Drinking Water Standard) under pasture fertilized with 220 kg N ha-1.