Effects of lignite application on ammonia and nitrous oxide emissions from cattle pens.

Beef cattle feedlots are a major source of ammonia (NH 3 ) emissions from livestock industries. We investigated the effects of lignite surface applications on NH 3 and nitrous oxide (N 2 O) emissions from beef cattle feedlot pens. Two rates of lignite, 3 and 6 kg m − 2 , were tested in the treatment pen. No lignite was applied in the control pen. Twenty-four Black Angus steers were fed identical commercial rations in each pen. We measured NH 3 and N 2 O concentrations continuously from 4th Sep to 13th Nov 2014 using Quantum Cascade Laser (QCL) NH 3 analysers and a closed-path Fourier Transform Infrared Spectroscopy analyser (CP-FTIR) in conjunction with the integrated horizontal flux method to calculate NH 3 and N 2 O fluxes. During the feeding period, 16 and 26% of the excreted nitrogen (N) (240 g N head − 1 day − 1 ) was lost via NH 3 volatilization from the control pen, while lignite application decreased NH 3 volatilization to 12 and 18% of the excreted N, for Phase 1 and Phase 2, respectively. Compared to the control pen, lignite application decreased NH 3 emissions by approximately 30%. Nitrous oxide emissions from the cattle pens were small, 0.10 and 0.14 g N 2 O-N head − 1 day − 1 (< 0.1% of excreted N) for the control pen, for Phase 1 and Phase 2, respectively. Lignite application increased direct N 2 O emissions by 40 and 57%, to 0.14 and 0.22 g N 2 O-N head − 1 day − 1 , for Phase 1 and Phase 2, respectively. The increase in N 2 O emissions resulting from lignite application was counteracted by the lower indirect N 2 O emission due to decreased NH 3 volatilization. Using 1% as a default emission factor of deposited NH 3 for indirect N 2 O emissions, the application of lignite decreased total N 2 O emissions. [ABSTRACT FROM AUTHOR]