Addressing Australian ammonia? How agriculture can reduce emissions

Written by Dr Xiuming Zhang, edited by Dante Romeo and Dr Boris Sarcevic

Nitrogen, whether from natural or artificial fertiliser sources, causes damage when large quantities are released into the environment.

Ammonia is one of the largest sources of nitrogen pollution. Its increasing emission not only degrades air quality, threatening human health, but also damages soils and waterways, harming ecosystems globally.

In Australia, agriculture is the largest emitter of gaseous ammonia (80%). These emissions represent a significant proportion of the 40% to 60% of applied nitrogen that our grazing and cropping systems lose to the environment. Such losses not only represent a significant cost to producers, but also impacts Australians’ health, and the environment. Despite this, ammonia emissions are not well-regulated in Australia and new policies may be needed to minimise their effects.

To help inform policy development, researchers at the ARC Research Hub for Smart Fertilisers at the University of Melbourne compiled and analysed data to produce an updated ammonia emission inventory for Australia. Additionally, agricultural management practices both on and off-farm were investigated for their potential to reduce ammonia emissions. The costs and benefits of different management practices were also assessed.

Results showed that Australia’s ammonia emissions could be reduced by as much as 32%. Ammonia mitigation is strongly in Australia’s interest, with an estimated implementation cost of 0.3 billion USD, resulting in a benefit of 3.1 billion USD, and significant benefits to health and the environment. As the largest contributors to Australia’s ammonia emissions (60%), intensive animal and cropping systems were found to be the most appropriate sectors for targeted ammonia emissions reduction. Changes to animal diet, housing, and manure management were recommended to reduce ammonia emissions in intensive animal production systems while improved fertiliser application, no-till practices, crop rotations with legumes, and crop residue recycling were recommended for intensive cropping systems.

Overall, mitigation of ammonia emissions on-farm could be incentivised by cost-effective measures as well as subsidies to offset the cost of implementing best-management practices. Additionally, effective communication of knowledge is necessary to enhance on-farm decision making.

To read more, visit here.

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Image credit: Robin Utrecht/Shutterstock.