Evaluating Deep Sowing of Oats in WA Production Systems

Key Messages:

• Deep sowing oats into stored summer moisture can boost early crop establishment and is particularly beneficial when autumn breaks are delayed or unpredictable.
• In 2024, 80–110 mm sowing provided stronger emergence and vigour than traditional 30 mm depths in medium and low rainfall zones due to stored soil moisture.
• Consideration of machinery capabilities, soil type, and seed variety is essential to successful deep sowing.

Project Summary:

This research project explores whether oats can be sown deeper than usual to tap into moisture from summer rain, supporting earlier sowing opportunities across WA’s wheatbelt. Small plot trials in 2024, led by Facey Group, tested sowing depths of 30 mm, 80 mm, and 110 mm using ten different oat varieties and several herbicide combinations.

Early findings show that deeper sowing increased early emergence and plant biomass, especially at 80- and 110-mm depths. Trials confirmed that oats long mesocotyl and coleoptile allow for deep sowing, with minimal emergence penalty. This allows growers to better use stored subsoil moisture and potentially reduce frost risk.

The project has provided evidence that oats can emerge reliably from depth, particularly when stored moisture is present. In parallel, a dedicated case study assessed machinery implications, including horsepower needs and tyne configuration.

Project Background:

WA grain growers face increasingly unreliable autumn breaks but often receive significant summer rainfall. Traditional sowing depths (around 30 mm) may miss deeper moisture reserves. Oats elongate the mesocotyl and coleoptile during emergence and may be suited to take advantage of this subsoil moisture if sown deeper.

Growers are already adapting sowing techniques to extend their seeding windows. This project responds to grower interest in early sowing oats by assessing how far current varieties can be pushed and whether deep sowing helps mitigate risks like dry starts and frost.

Further Information

Project Start Date:

• January 2024

Project End Date:

• April 2026

Project Funding:

• GRDC National Grower Network (NGN)

Project Lead:

• Tina Astbury, CEO – Facey Group

Project Collaborators:

• Facey Group
• Merredin & Districts Farm Improvement Group (MADFIG)
• Living Farm
• InterGrain
• Analytics for the Australian Grain Industry (AAGI)

Host Farmers:

• Curtis Liebeck & Tess Lewis (Merredin)
• Ken Martin & Lee Parker (Wickepin)