Effects of inhibitor use on nitrous oxide emissions from application of urea to pastures. Noorat, Victoria, 2012-2013 and 2014-2015 [Theme 1: Inhibitors for reducing emissions]

Brief description

Data included in the package; - standard site weather data (daily) - soil temperature (50 mm) and surface soil water content (volumetric) - nitrous oxide flux data, derived from manual chamber measurements (variable time steps) -– all plots.average for treatment Experimental design (5 treatments by 5 blocks),. tTreatments (1) No nitrogen applied, (2) 50 kg N / ha as urea after every second defoliation (simulated grazing), (3) 50 kg N / ha as urea coated with nitrification inhibitor (dicyandiamide) after every second defoliation [Note this treatment was replaced in the study by UAN (urea ammonium nitrate) in July 2013, (4) 50 kg N / ha as urea coated with nitrification inhibitor (DMPP) after every second defoliation, and (5) 50 kg N / ha as urea coated with urease inhibitor (nBPT) after every second defoliation. All herbage was removed from plots at each harvest, other fertiliser inputs annually based on soil tests. Experiment commenced in July 2012 and yield assessments continued until March 2015, on a dermosol (derived from quaternary volcanic tuff and scoriaceous deposits) near Noorat (38o10'S, 142o58'E) Objective: To assess the potential for inhibitors to reduce emissions of application of urea to pastures. Ffertiliser was applied 19 July 2012, 22 Sept 2012, 19 September 2013, 7 November 2013, 19 June 2014 and 21 August 2014. Emissions were measured using static chambers (0.5*0.5*0.2m) - these were deployed at the Noorat site prior to measurement commencing. Flux based on linear equations, sampling times time 0, 20, 40 and 60 minutes and 0, 30 and 60 minutes after chamber deployed in the first and second year of emission measurements respectively.. Measurements commenced 19 July 2012 and ended on 5 July 2013, measurement recommenced 20 June 2014 and ended on 13 April 2015.