A technique combining open-path Fourier transform infrared spectroscopy (OP-FTIR) with an inverse dispersion model (backward Lagrangian stochastic technique, bLS) was used to quantify CH₄, N₂O and NH₃ emissions from a feedlot. The daily averaged NH₃ flux was 192 g head^-1 d^-1, nearly three times IPCC Tier II modelled estimates, accounting for about 70% diet nitrogen. For average size feedlot of 15,000 to 20,000 cattle in Australia the daily ammonia loss is equivalent to 6 tones urea fertilisers.  Application lignite reduced NH₃ loss by 65%, resulted in much higher (about 3 times) N content in manure comparing to the control. The application of N rich manure to irrigated sorghum increased the biomass yield by 40%.