Ammonia and greenhouse gas emissions from beef feedlot surface material treated with aluminum sulfate (alum) or microbial amendments.

Abstract

A lab-scale study evaluated ammonia (NH3 ) and greenhouse gases, emissions when aluminum sulfate (alum) or a microbial product were added to beef feedlot surface material (FSM). Three kilograms of FSM and 1.5kg of water were added to stainless steel pans (50cm × 30cm × 6.5cm). Treatments included a control (no amendment), 450g alum, or 0.5g microbial product. The pans were placed in an environmental chamber that was maintained at 23°C and 50%-60% humidity. Emissions were measured three times weekly for 3 weeks. Ammonia, N2 O, and CH4 were lower (p<0.01) from pans with amendments compared to the control pans; emissions from the FSM that received the microbial treatment were lower than the FSM treated with alum. Methane emissions were similar for the control and alum-treated FSM but lower (p<0.01) for the FSM that was treated with the microbial product. Nitrate-N was lower, and NH4+ -N and total sulfur concentrations were higher in FSM treated with alum compared to no treatment or the microbial treatment (p<0.01). Results indicate that both alum and microbial amendments have benefits in reducing emissions from the feedlot surface, with the microbial product providing additional reductions in emissions compared to the alum.