Click on “Download PDF” for the PDF version or on the title for the HTML version.
If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.
Evaluation of calcium ammonium nitrate and urea-based fertilisers applied to grassland in Ireland
Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.org
Citation: Paper number 131620284, 2013 Kansas City, Missouri, July 21 - July 24, 2013. (doi: http://dx.doi.org/10.13031/aim.20131620284) @2013
Authors: Diogenes Luis Antille, Nyncke J. Hoekstra, Maria --- Ernfors, Karl --- Richards, Stanley T.J. Lalor
Keywords: Urea calcium ammonium nitrate nBTPT fertiliser use efficiency temperate grassland
Abstract. This study investigated the influence of N source and rate, and timing of N application on dry matter yield (DMY), N responses, N uptake and N use efficiency (NUE) in a grass crop. The experiment used three fertiliser treatments: CAN, urea and nBTPT-coated urea (nBTPT-U), three N rates (0 – control, 25, 50 and 75 kg ha-1), and 18 fertiliser application timings. The agronomic performance of urea was lower than CAN in early spring. This included relatively lower N responses, lower relative DMY (90%) and N uptake (85%) which translated in lower NUE (0.45 vs. 0.70 kg kg-1). For N applications later in the spring both urea and nBTPT-U showed relative DMY and NUE which were within ±5% compared with CAN (100%). nBTPT enhanced the overall performance of urea which was shown with increased temperature towards the summer or increased N rates. In the summer, the efficiency of urea was lower than CAN or nBTPT-U in all measured parameters. The variability of urea and nBTPT-U as N-sources for grass was comparable to CAN but DMY with urea was ≤95% that of CAN (100%) at 8 out of the 19 application timings. Increasing the application rate of urea-N to offset its relatively lower efficiency may not be recommended since DMY of urea-N relative to CAN decreased with increased N fertilisation levels. However, with the use of nBTPT this may be possible, but fertiliser choice needs to be based on the relative costs per unit N.
(Download PDF) (Export to EndNotes)