‘Converting rainfall into profit’: GRDC spring and summer crop trials to address waterlogging

Headshot of Shannon Verhagen
October-sown canola at the South Stirlings single-species demonstration site.
Camera IconOctober-sown canola at the South Stirlings single-species demonstration site. Credit: Daniel Fay/Supplied

A new grower-driven project trialing spring and summer crops is set to explore production opportunities for WA farmers grappling with the impacts of waterlogging off the back of the wettest year in decades.

Three multi-species validation spring and/or summer-sown field trials are taking place at sites in Jerramungup, Boyup Brook and Green Range, with at least one cereal, brassica and legume sown where possible.

The 18-month Grains Research and Development Corporation-funded project led by Stirlings to Coast Farmers will be of particular relevance to growers in the medium-to-high-rainfall zones of the lower Central Wheatbelt, Great Southern and South Coast.

SCF chief executive Nathan Dovey said it would aim to improve the knowledge and confidence of growers to profitably sow a crop in spring or summer on paddocks where winter crops or pastures failed due to waterlogging or where soil moisture levels permit.

“It’s about converting rainfall into something profitable,” he said.

“Unlike years ago, we now have the plants to work with — we just need to improve our understanding of how they fit into our farming systems for the greatest impact.”

Each trial will be assessed for weed numbers, pest pressure and management, plant available soil moisture, soil nutrition and erosion control over summer, and the overall productivity of the spring-sown crops and following winter-sown crops.

Each will have at least three treatments as well as a “standard grower practice” control.

Grower groups will also measure the productivity of winter canola, winter wheat and sorghum at four single-species trials at South Stirlings, Mobrup, Wickepin and Lake Cairlocup.

In addition to the farm-scale demonstrations, a summer grains small plot trial will be conducted.

Nutrien Ag Solutions will also conduct a randomised exploratory summer grains small plot trial.

“Overall, the project will be local grower and adviser-driven so that solutions demonstrated in the field are both practical and locally relevant,” Mr Dovey said.

“Practicalities such as access to seed, seeder/harvester set-up and grain quality, drying and marketability are also being considered as part of the research.

“All costs and potential profits will be factored into reporting to ascertain the true value of this rotational tool to the farming system.”

Case studies will be developed about growers who have planted either an August or September-sown fast-maturing winter crop, spring-sown summer crop, or a summer crop after winter crop harvest, to evaluate their experiences and the profitability of their management decision.

Summer crops have been grown with varying degrees of success on the South Coast for more than 50 years, with previous GRDC research finding summer forage crops not only to provide grazing opportunities, but delay the onset of salinity and providing nitrogen to following winter crops.

GRDC grower relations manager (West) Lizzie von Perger said the initiative — dubbed “Locally relevant spring and/or summer sown cropping opportunities for grain growers following excessive winter waterlogging – South-Western Australia” — would include crop types and varieties previously not available.

“It will build local grower and adviser knowledge to inform decisions when managing excess soil moisture,” Ms von Perger said.

“The project will focus on the key management aspects raised by growers at the GRDC’s 2021 winter National Grower Network meetings — namely weed and erosion control in waterlogged areas, making use of the excess water to produce additional grain and/or forage, and understanding impacts on the following winter crop, such as soil moisture/salt levels, root architecture and biomass, as well as soil nutrient levels and distribution.”

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