National Hay Agronomy project aims to elevate Australia's oaten hay exports
In 2022-23, the Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES) reported that oaten hay exports were valued at approximately $349 million, with Western Australia (WA) accounting for over 40% of the national total.
Fluctuating hay yields and quality highlight the need for updated farming guidelines to improve yields and hay quality.
To strengthen Australia’s position as a leading supplier of high-quality oaten hay, AgriFutures launched the 4-year National Hay Agronomy (NHA) project in 2019, in collaboration with the Department of Primary Industries and Regional Development (DPIRD)
The project aims to encourage the adoption of new hay varieties and agronomic practices by delivering research and guidance to farmers.
The 3 key objectives included developing improved agronomic guidelines by June 2022, reporting on the use of growth regulators, and updating disease management strategies for issues like red leather leaf and septoria.
Trial program
The agronomy component of the NHA project made significant strides over its 4-year span by undertaking several important studies.
The team conducted 12 agronomy trials to understand how oat varieties react to different planting times and nitrogen levels, focusing on how these factors influence both yield and quality of hay.
From there, researchers tested 5 new oat varieties at 3 separate locations in 2021 to assess their performance.
From 2019 to 2021, replicated field trials were carried out at Muresk in WA and at other locations throughout Australia.
Early sowing benefits
Sowing early is essential for maximising both yield and grain quality in milling oats, however, this practice does not yield the same benefits for hay oats.
Early sowing may lead to increased hay yields, but often at the expense of hay quality.
Typically, hay from early-sown crops has denser stems, elevated levels of fibre, and reduced levels of crude protein and water-soluble carbohydrates (WSC).
This was not consistent across sites and years but was the general trend when the data from all sites were averaged.
The project revealed that oat varieties exhibit diverse responses to sowing dates, which are challenging to predict before the growing season or at the time of sowing.
This underscores the need for further research into variety-specific responses to sowing dates, particularly as new varieties of oaten hay are being tested by the industry and InterGrain.
Determining the optimal time for cutting is crucial for growers and advisors to choose suitable varieties and plan effective hay management strategies for the spring season.
DPIRD’s “FlowerPower” for oats model is one tool that WA growers could use for this purpose, but phenology data for new oat varieties are needed.
Other findings
Research on optimising nitrogen rates for oat hay production in the NHA project has shown that nitrogen (N) promotes more biomass, resulting in taller and greener plants.
However, it also increases the risk of lodging, particularly in susceptible varieties.
The optimal hay yield was achieved with an application of 90 kg N/ha, averaged across different varieties and locations.
In some locations, the target nitrogen level was reduced due to below-average rainfall during critical growth periods.
Nitrogen was not a significant factor in causing hay quality defects such as thick stem diameter, high acid detergent fiber (ADF), high neutral detergent fiber (NDF), or high lignin content.
It did, however, increase crude protein levels and decrease WSC.
Applying more than 90 kg N/ha posed a risk of failing to meet the industry's minimum standard of 22 per cent WSC for premium hay.
Different varieties showed similar responses to increased nitrogen in terms of hay quality traits.
A key distinction is that varieties with higher genetic levels of WSC can tolerate more nitrogen before their quality grade decreases, allowing for potentially greater hay production at the same quality level.
The study also found that the planting date did not significantly affect the response to nitrogen, despite variations in agronomic traits, hay yield, and quality parameters (excluding greenness, ADF, and NDF) across different planting dates.
The response to nitrogen was generally consistent between planting dates, though the impact varied.
Over the 3 years the research was conducted (2019 to 2021), seasonal conditions and varietal differences were more influential in determining hay quality than the rate of nitrogen applied.
Variety performance
The four-year NHA project assessed the hay yield and quality of four dual-purpose varieties, Carrolup, Durack, Williams and Yallara and four hay-only varieties Brusher, Koorabup, Mulgara and Wintaroo.
Brusher and Wintaroo were the leading varieties for hay yield at the first sowing date, while Wintaroo had the highest yield of the second sowing date.
Of the eight varieties evaluated, Yallara had the best overall hay quality nationally, with the highest WSC and lowest fibre levels (ADF and NDF) combined with thin stems (data not shown).
Yallara hay yield was comparable to the specialist hay varieties Brusher and Wintaroo, with a lower lodging risk and similar hay colour.
DPIRD Research Scientist Georgie Troup said given the variability in response to delayed planting, it is advisable for farmers to have two varieties in their system.
“This diversity can help manage risks associated with disease and optimise hay cutting timing while aligning with the quality demands of their hay exporters,” she said.
Funding partners/project collaborators
AgriFutures
South Australian Research and Development Institute
Agriculture Victoria
New South Wales Department of Primary Industries
Birchip Cropping Group
More information
Click here to read the GRDC webpage National Hay Agronomy – improving the outcomes of oaten hay in the rotation
Contact
Georgie Troup
DPIRD Research Scientist (oats)
E: Georgina.Troup@dpird.wa.gov.au
P: (08) 9690 2215