A multi-million-dollar suite of projects investigating innovative solutions to Western Australia's challenging and yield-limiting soils is coming to a close after five years of intensive research.

The Soil Constraints West project, co-invested by GRDC and the Department of Primary Industries and Regional Development (DPIRD), has been a ground-breaking initiative - searching for strategies to combat WA's four main soil constraints of:

• Compaction
• Water repellence
• Acidity
• Sodicity.

Project manager Chris Gazey believes the project could prove to be one of the most significant industry investments in recent decades, providing growers with multi-pronged tactics to tackle soil constraints.

He says with the introduction and subsequent almost-total uptake of no-till farming practices over the past 25 years, soil constraints, particularly compaction and water repellency, have been increasing in their severity, impacting significantly on grain yields over the past decade.

He says the hit-and-miss research approach to managing soil constraints is now a thing of the past, with all aspects of the industry recognising the need for a coordinated campaign to manage all constraints.

"In many cases, soils will have more than one constraint,” he says.

“Tackling individual constraints in isolation may not provide the most cost-effective or productive solution.

"Under the overarching Soil Constraints West banner, the challenges of the four different soil constraints can be viewed as a total package, with solutions provided to growers as a whole, rather than in isolation."

Some key soils research undertaken included:

Compaction - Trials included assessing the value of deep ripping, with and without topsoil inclusion.

Water repellency - Research focused on mitigation strategies and longer-term amelioration tactics.

Acidity - Lime application trials, with and without incorporation were set up across the wheatbelt.

Sodicity - Trials included investigating the impacts of soil amelioration strategies, such as delving and deep-ripping.

Project outcomes

Soil Constraints West was a $33 million investment in projects that will conclude in June this year. Trials were set up righta cross WA’s wheat-belt and key findings were made into tactics of:

• Inversion tillage
• Deep-ripping
• Lime incorporation
• Gypsum application
• Water harvesting
• Improved mapping of soil constraints
• Development of decision making tools.

Mr Gazey says growers are now better equipped to understand how and why their soils are restricting plant growth.

"Through this project, we have talked with hundreds of growers and advisers across the state,” he says.

“There is now a new focus on re-engineering soils to remove constraints and work towards achieving yields that our soils can be capable of.”

While the Soil Constraints West project has ended, a new $48 million co-investment by GRDC and DPIRD will take soil health research to new levels.

More information: Chris Gazey, DPIRD, chris.gazey@dpird.wa.gov.au