A report from a study, to update the estimates of the average carbon footprint of a range of fertilisers used in New Zealand by Ballance Agri-Nutrients and Ravensdown, has been released.

The Fertiliser Association of NZ-commissioned study was based on local production and importation data for NZ fertilisers in 2010.

The report was written by Dr Stewart Ledgard, who is a principal scientist with AgResearch and an Adjunct Professor of the Life Cycle Management Centre at Massey University.

His research focus is the management of resource use and environmental impacts of pastoral farming systems. During the last decade this has involved application of Life Cycle Assessment across a range of NZ agricultural systems and products.

Life cycle assessment methodology was used to account for all sources of greenhouse gas emissions in calculation of the carbon footprint of fertilisers, including that for transportation to a NZ port.

The report provides the NZ fertiliser industry with information on the GHG emissions associated with the production and use of fertilisers on Kiwi farms. It also determines the contribution of fertilisers to the total GHG emissions from NZ dairy, sheep and beef production.

“Use of data from this project will enable the fertiliser industry to examine the ‘hot-spots’ in GHG emissions throughout the life cycle in the production and use of fertilisers in the primary sector,” says Stewart.

FANZ chief executive Vera Power says it’s very positive to see that the results have shown a decrease between 2010 and 2018/2019 in the average carbon footprint of most fertilisers used by these companies “due to greater efficiencies across production and transportation and changes in the source of raw materials”.

“For urea fertiliser and superphosphate these represent an eight per cent reduction and 28 per cent reduction respectively.”

Emissions from shipping of raw materials to NZ was the largest contributor to the carbon footprint of superphosphate. The results also show a reduction in the contribution of nitrogen plus non-nitrogen fertiliser carbon footprint for milk from 8.5 per cent in a 2008/2009 study, to eight per cent in this study.

For typical North Island sheep and beef products, the contribution of fertiliser to the carbon footprint was assessed at 2.8 per cent and to the whole farm carbon footprint 1 per cent.

The full report is available at: http://www.fertiliser.org.nz/Site/news/articles/update-of-the-carbon-footprint-of-fertilisers-used-in-new-zealand.aspx