Greenhouse gas emissions from intensive beef manure management.

Summary

Emissions of GHG's from manure management at Australian feedlots are uncertain, and inventory estimates are largely unverified. There is a lack of understanding of the factors that control emission in Australian manure management systems, where conditions of climate and practices differ greatly from the overseas (often non-feedlot) sources of the data on which the inventory is based.
Despite this uncertainty, inventory estimates account for nitrous oxide emissions from feedlot manure management as the second largest Australian agricultural manure management emission source.
Where these manure emissions are significant, decreasing them may constitute a simple opportunity for emission mitigation. Failure to act in this regard presents the very real risk of missing the 'low hanging fruit' in the rush towards a meaningful response to climate change. To this end, we established the major emissions from each manure management system element in relation to the whole.
The key finding was that aggregate emissions from pen manure, compacted stockpiles, and composting were far less than the inventory protocols suggest. Volatilisation of ammonia from the operation is likely substantially higher, though the study suggests there is reason to question the way these values are used to calculate indirect nitrous oxide emissions.
Federal legislation in this area is probably still in flux. However, the results of these studies enable fairer attribution of emission costs to the industry overall, and will decrease any future undue burden associated with those industry emissions on individual producers. There is also scope for the advances in management responsive to enable reward of improved management practices.