Key points

WA soils research initative 2019-23:

• GRDC and DPIRD have invested in a new soils initative to address WA's common constraints
• This aims to develop tactics to boost water and nutrient-use efficiency and grain profits
• A range of soil amelioration tactics will be trialled
• These include strategic tillage, liming and furrow formations.

Soil amelioration strategies in Western Australia's northern agricultural sandplain region came under the spotlight recently when researchers, growers and industry consultants toured the region over two days.

Sponsored by GRDC, the Western Australian Department of Primary Industries and Regional Development (DPIRD) and SoilsWest, the tour group saw first-hand the productivity results from alleviating multiple soil constraints within the soil profile.

Researchers and growers from north and south of Geraldton presented their findings, highlighting the importance of managing and maintaining beneficial soil properties after the amelioration.

With the aid of soil pits, DPIRD scientists Dr Stephen Davies, Wayne Parker, Chad Reynolds, Dr Gaus Azam and Dr Giacomo Betti illustrated the importance of changing farming practices to alleviate soil constraints throughout the soil profile.

Strategic deep tillage

"Strategic deep tillage that improves the incorporation of soil amendments, de-compacts the soil and alleviates water repellence, acidity and compaction, was a key topic of the tour," Dr Davies says.

Strategies such as fertiliser application, traffic management on soft soils, liming, plant disease management and amelioration costs were presented.

In situations where there were multiple soil constraints, growers were interested in which soil constraint to tackle first.

"On deeper soils with multiple constraints, knowing which constraint or combination of constraints to tackle first given the large investment to ameliorate soil is important," Dr Davies says.

"Evidence from the sites we visited indicated that overcoming compaction is critical, but where subsoil acidity was a problem, having a long and robust liming history was an advantage - using deep mixing to move limed soil deeper in the profile."

GRDC has produced a video outlining tips for crop establishment following strategic deep tillage.

Industry collaboration significant

DPIRD senior research officer David Hall says industry collaboration, as evidenced by the tour, was an important way to recognise the work of all industry participants in improving productivity in a hard-to-manage soil type.

Mr Hall says findings from specific research undertaken on the northern sandplain has shown there is an 80 per cent chance of increasing grain yields by 0.5 tonnes per hectare per year by undertaking strategic tillage.

"To date, at least 200,000ha of land has been transformed in this way, which is quite incredible," he says.

Mr Hall believes agricultural engineers also play an important role, developing the most appropriate machines to improve soil productivity.

"The tour of a local manufacturer was a highlight because they build machinery suited to WA conditions and requirements," he says.

"Interestingly, as a group, the industry participants on this tour manage or influence farming practices on more than one million hectares of cropping land in WA."

It is hoped the tour will become an annual event, showcasing different regions of WA's grainbelt each year.

More information: David Hall, david.hall@dpird.wa.gov.au