A new cost-effective method to mitigate ammonia loss from intensive cattle feedlots: application of lignite

Abstract

In open beef feedlot systems, more than 50% of dietary nitrogen (N) is lost as ammonia (NH3). Here we report an effective and economically-viable method to mitigate NH3 emissions by the application of lignite. We constructed two cattle pens (20 × 20 m) to determine the effectiveness of lignite in reducing NH3 emissions. Twenty-four steers were fed identical commercial rations in each pen. The treatment pen surface was dressed with 4.5 kg m−2 lignite dry mass while no lignite was applied in the control pen. We measured volatilised NH3 concentrations using Ecotech EC9842 NH3 analysers in conjunction with a mass balance method to calculate NH3 fluxes. Application of lignite decreased NH3 loss from the pen by approximately 66%. The cumulative NH3 losses were 6.26 and 2.13 kg N head−1 in the control and lignite treatment, respectively. In addition to the environmental benefits of reduced NH3 losses, the value of retained N nutrient in the lignite treated manure is more than $37 AUD head−1 yr−1, based on the current fertiliser cost and estimated cost of lignite application. We show that lignite application is a cost-effective method to reduce NH3 loss from cattle feedlots.

Beef and coal are key drivers of Australia’s high nitrogen footprint

“…1, Supplementary Table 4). In particular, ammonia (NH 3 ) emissions from the grazing system are estimated at 0.2 kg NH 3 -N/kg manure N39 but 0.81 kg NH 3 -N/kg manure N in the feedlots2136. That means that when producing the same amount of beef, more Nr is released to the environment from feedlot systems than from grazing farms.…”

“…The widespread use of agricultural land in Australia has led to issues such as mining soil N in dryland rain-fed wheat systems and excessive N use in feedlot animal production systems1819. Although numerous studies have linked agricultural Nr to environmental problems202122, the N footprint has not been quantified for Australia. The objectives of our study were therefore to: (1) assess the Nr loss driven by food and energy consumption and associated production in Australia using the N-Calculator model; (2) benchmark Australia’s performance of Nr loss against other countries; and (3) explore the driving forces and mitigation strategies for the Australia’s N footprint.…”

Using nitrification inhibitors to mitigate agricultural N2O emission: a double‐edged sword?

“…In this regard, substances with a high affinity for binding onto NH 4 + ions may be used as additives to mitigate NH 3 volatilization. For instance, zeolite and, more recently, lignite were shown to effectively lower NH 3 volatilization when mixed with animal manure (Ndegwa et al, 2008;Chen et al, 2015). Alternatively, where practical, manure should be incorporated into soil rather than being surface applied to prevent NH 3 loss.…”

Broiler Litter × Industrial By‐Products Reduce Nutrients and Microbial Losses in Surface Runoff When Applied to Forages

“…Lignite (brown coal) is a low‐grade coal with low heating values, is acidic in nature, has a high humic acid content and high cation exchange capacity, and contains up to 20% of labile C, all of which may suppress NH 3 volatilization from manure (Chen et al, 2015; Li et al, 2011; Sun et al, 2016). Lignite can be used as a soil amendment and has the potential to reduce manure pH (Bernal et al, 2009) and to limit volatilization of NH 3 (Hartung and Phillips, 1994).…”

“…Lignite can be used as a soil amendment and has the potential to reduce manure pH (Bernal et al, 2009) and to limit volatilization of NH 3 (Hartung and Phillips, 1994). Application of lignite to a feedlot pen decreased NH 3 loss by approximately 66% (Chen et al, 2015). Lignite is the most common source of organic acid (humic acid) and has the potential to chelate nutrients (Kalaichelvi, 2006).…”