A national research program examining improved efficiency fertilisers will aim to give Australian grain farmers the tools to improve nitrogen use efficiency and reduce on-farm greenhouse gas (GHG) emissions.
Enhanced efficiency fertilizers (EEFs) use chemical or physical approaches to regulate nitrogen release and availability to plants. They aim to reduce the risk of nitrogen loss by better synchronizing fertilizer application with crop needs.
The University of Melbourne will lead the four-year, $17.33 million project, which is an investment by the Grains Research and Development Corporation (GRDC), in partnership with several research organisations and industry partners including CSBP Limited, Incitec Pivot Fertilisers, Nutrien Ag Solutions, N-Shield and Fertiliser Australia.
Helen Suter, Associate Professor at the University of Melbourne and project leader, said a number of EEF technologies are commercially available, but relatively little is known about their effectiveness in different climates and agroecosystems, and their economic and environmental benefits to the grain industry.
“Growers are looking for recommendations on which technologies work where, when, why and how, to make informed decisions about their nitrogen management strategies,” said Associate Professor Suter.
“The project will establish a network of field trials across Australia in representative soils and cropping systems, where commercially available EEF technologies will be evaluated alongside conventional nitrogen fertilisers.
“These technologies include urease inhibitors (to reduce ammonia losses), nitrification inhibitors (to reduce nitric oxide, nitrogen and leaching losses), dual inhibitors (urease and nitrification) and controlled release fertilizers (both targeting all loss pathways).”
GRDC chief executive Nigel Hart said the strategic investment had been developed in response to the needs of grain producers, with input cost management and sustainability at the core of the industry’s concerns.
“As an organisation investing on behalf of Australian grain growers, we are keenly aware of the pressures our sector faces due to high input costs, particularly nitrogen. Ensuring we are using the most effective fertilisers in the most efficient way is very important,” Mr Hart said.
“This research by our partners at the University of Melbourne is critically important amid a growing need to understand and reduce emissions where we can, as part of the long-term sustainability goals of farms and Australian agriculture more broadly.”
Controlled environment studies will complement field activities, providing a mechanistic understanding of soil nitrogen cycling and loss pathways, and support modelling activities aimed at quantifying the environmental impact and potential nitrogen use efficiency gains associated with the use of EEFs in the grain industry.
The EEFs tested will target the main nitrogen loss mechanisms (denitrification, nitrate leaching, volatilization) in different growing regions and quantify nitrogen uptake by crops to determine nitrogen use efficiency and return on investment.
This objective will be achieved by using fertilizers marked with the stable isotope of nitrogen 15, which will make it possible to monitor the fate of fertilizers in soils and plants.
GRDC Sustainable Growing Systems Manager Cristina Martinez said EEFs had been discussed at several GRDC National Grower Network (NGN) forums, including in Western Australia, and were at the forefront for many growers given increasing sustainability demands.
“Enhanced efficiency fertilizers are a potential option to reduce GHG emissions on farms while improving nitrogen use efficiency,” Dr. Martinez said.
“There are several reasons for their low adoption among cereal producers, including their higher cost – compared to standard fertilizer products – and uncertainty about their behavior and performance in the field as well as the return on investment they offer.
“This investment by GRDC will demonstrate the effectiveness of these alternative fertilizer technologies within the grain industry and provide producers with clear recommendations on which technologies will perform best in their production systems to maximize return on investment.”
Research partners in the project include the University of Melbourne, Western Australia Department of Primary Industries and Regional Development, University of Queensland, New South Wales Department of Primary Industries, CSIRO, Queensland Department of Environment and Science, Queensland University of Technology, La Trobe University, Birchip Cropping Group and Hart Field Site Group.