A national study measuring greenhouse gas emissions from crop residues is set to help the grains industry accurately report its carbon footprint
An $8 million national study led by the Queensland University of Technology (QUT), will measure greenhouse gas emissions (GHG) from the decomposition of crop residue, with potential benefits for future market access and price.
QUT Professor David Rowlings, a soil scientist in the sustainable agriculture program at the university’s Centre for Agriculture and Bioeconomy, will lead the project – which will involve two years of fieldwork across a range of crop types, climates and soils.
Crops such as cereals, oilseeds and legumes will be tested at five sites across the country, including Gatton (Queensland), Tamworth and Wagga Wagga (New South Wales), Horsham (Victoria) and Wongan Hills (Western Australia).
QUT says GHG emissions attached to grains can impact the price and marketability of exports, as well as the sustainability credentials of farm businesses, so it is expected that the study will have significant benefits for growers and marketers.
Crop residues emit GHG as they decompose in the paddock, Rowlings says, with nitrous oxide making up most of these emissions.
“Australia includes these emissions in its sector-level accounting to the Intergovernmental Panel on Climate Change (IPCC),” he says.
“While the global default emission decomposition factor is one per cent of total residues, international research has shown that 0.5 per cent may be more accurate for dry climates.”
Rowlings adds that this research has been accepted by the IPCC, and the CSIRO is currently updating the nation’s GHG baseline methodology – with support from the Grains Research and Development Corporation (GRDC) – to use the lower emission factor from this year.
However, with approximately 23 million hectares of land under cropping, Rowlings says growers can still benefit by being able to use accurate, locally derived emissions data for IPCC reporting.
At each trial site, nitrous oxide will be measured for the 12 months following harvest to gain accurate data on the emissions from the decaying crop residues.
Crops being studied include wheat, faba beans and canola in NSW and Victoria, sorghum, wheat and faba beans in Queensland, and wheat and canola in WA.
The research builds on earlier work done by GRDC in partnership with CSIRO for the Australian Grains Baseline and Mitigation Assessment.
This 2022 report showed crop residue accounted for 20.4 per cent of all Scope 1 (on-farm) GHG emissions in Australian cropping – more than fertiliser (15 per cent), lime application and other farm operations (11 per cent each).
The initial study also concluded that the use of internationally derived emissions factors may be overestimating reportable GHG emissions from the Australian grains sector.
Trial sites will be coordinated and monitored by the project’s research partners including Agriculture Victoria, University of Queensland and the departments of Primary Industries and Regional Development in both NSW and WA.
To learn more about the program or apply visit agriculture.vic.gov.au.