Adjusting nitrogen fertiliser applications on grain crops can reduce greenhouse gas emissions and boost profitability, according to detailed analysis led by the Department of Primary Industries and Regional Development (DPIRD).
Researchers investigated changes in farm business profitability and emissions from different nitrogen and liming strategies using bio-economic modelling simulation across 14 Western Australian locations.
The findings will be presented by DPIRD research scientist Sud Kharel at the 2024 GRDC Grains Research Update in Perth on Monday, February 26 and Tuesday, February 27.
"Simulations using the Economic Valuation of Alternative Land Use Sequence (EVALUS) model were conducted for sites across the grainbelt in 2023," Mr Kharel said.
"Adjusting nitrogen applications during the season led to increased gross margins and reduced emissions in all study locations, particularly in higher rainfall locations.
"Modelling of nitrogen application strategies aimed at maximising profit, rather than yield, always resulted in lower greenhouse gas emissions."
However, the analysis found neglecting lime applications to reduce emissions would likely reduce farm profit.
Mr Kharel said the analysis highlighted that growers had the opportunity to select nitrogen strategies that maintain profitability and reduce emissions.
"This is likely to be a more effective and sustainable approach to targeting emission reduction than limiting lime application," he said.
"While higher emissions resulted from liming, as expected, farm profitability increased due to the ability to continue profitable cropping options in the rotation, making the investment in liming cost-effective."