Submitted to: American Society of Agricultural Engineers Meetings Papers
Publication Type: Abstract Only
Publication Acceptance Date: 5/3/2004
Publication Date: 8/1/2004
Citation: Parker, D.B., Pandrangi, S., Greene, L.W., Almas, L.K., Rhoades, M.B., Cole, N.A., Koziel, J. 2004. Application rate and timing effects on urease inhibitor performance for minimizing ammonia emissions from beef cattle feedyards. American Society for Agricultural Engineers. Paper No. 044080.
Technical Abstract: A laboratory study was conducted to evaluate how rate and timing of urease inhibitor application affects ammonia emissions from simulated beef cattle feedyard surfaces. The urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT) was applied at rates of 1 and 2 kg/ha, at 8, 16, and 32 day frequencies, and with or without simulated rainfall. Synthetic urine was added every 2 days to the manure surface. Ammonia was trapped in a sulfuric acid solution using a vacuum system and analyzed for nitrogen using automated procedures. NBPT applied every 8 days and at 1 and 2 kg/ha resulted in 51.6 and 67.5 percent reduction in ammonia emission rates, respectively. Only the NBPT applied every 8 days was effective in reducing ammonia emissions, indicating that NBPT should be applied every 8 days or less. The 8-day, 1 kg/ha NBPT treatment had the most promising cost-benefit ratio of 1.26. Simulated rainfall had little effect on the performance of NBPT, indicating that moisture content has little effect on NBPT performance.