Dishing the dirt on VRT & Saline Soils across Upper EP

There’s no doubt about it, low rainfall seasons push farmers and their systems to the limit. And during such long, dry conditions, our soils appear to be feeling the pinch. Vulnerable areas that we finally managed to maintain cover on now resemble balding middle-aged men.

Such a shame……for the men and the soil.

When you hear the words “soil research”, it’s hard not to think “but that’s been looked at for the last 20 years”. I know I’m guilty of thinking the very same thing. But on the flip side, what happens below the surface is much like exploring the galaxy – there seems to be endless possibilities.

Which is why having access to great soil management expertise, tools and resources can be the best way to move forward with these problematic patches.

Kicking off with Saline Soils & VRT Workshops, over 40 farmers, advisors, researchers and industry representatives attended the events held in Kimba, Minnipa and Ceduna to hear from leading soils experts, Dr Chris McDonough of Insight Extension for Agriculture and Dr Sean Mason of Agronomy Solutions.

Dr McDonough led the dry saline soils management sessions for each workshop. Content covered how saline soils function, along with management strategies available, what worked well, and what should be avoided in some rainfall situations and with certain soil types.

Key messages for managing dry saline soils included:

• Mulching soils through spreading sand, straw or chaff during dry summer periods to reduce evaporation and wicking of salts to the surface.
• Retaining as much ground cover as possible on vulnerable areas.
• Removing livestock from dry saline soils.

Dr Mason led the sessions on VRT, which emphasised the need for farmers to know the soil types and pH across their paddocks.

Useful tips for farmers looking to apply VRT on-farm included:

• Knowing the unique zones in each paddock in order to respond with the best inputs for those areas.
• Combining Normalised Difference Vegetation Index (NDVI) mapping and Google Earth maps to identify paddock soil types, then layering soil pH and NDVI maps to identify areas of phosphorous deficiency.
• Investigating poor performing paddock areas and using high-performing areas as a benchmark for comparison.
• Conducting phosphorous strip trials on-farm to help determine application rates and set an input budget.

AIR EP Executive Officer Naomi Scholz said the workshops aimed to equip farmers with proven, cost-effective soil and fertiliser management practices to build resilience and yield potential.

“Farmers on the EP face specific challenges with soil management and looking after dry saline soils is one area that can be difficult,” Ms Scholz said.

“The workshops gave growers and other industry leaders a detailed understanding of how saline soils function and their impact on plant growth. The sessions also detailed some of the effective soil management strategies available. It was a great opportunity for farmers to ask our presenting experts questions about the specific issues they’re seeing out in the paddock, and to share the successes and challenges they’ve had with different management techniques.

“The variable rate technology (VRT) session was also extremely helpful in demystifying how farmers can apply this approach to their own properties to increase farm operation efficiencies and support soil management and crop growth.

“The feedback that we’ve had so far was that farmers left the workshops with a better understanding of their properties’ soil constraints and potential, had learnt how to zone paddocks easily for variable rate application, and felt confident that they could implement the basics of VRT.”

As a direct result of the workshops, may farmers identified the following practice changes they would implement to address their current soil constraints:

• Maintaining ground cover on dry saline patches
• Spreading hay/straw/chaff/sand
• Explore saline amelioration options
• Remove grazing, spread sand, modify rotation

Decision trees for fixing saline soils (dry saline soils and Mallee seeps) can be found on the Mallee Sustainable Farming website: https://msfp.org.au/projects/fixing-saline-soils/

Featuring next week: Digging deeper into sandy soils with Brett Masters, EPAG Research and James Cant, AGRA Agronomy at the Franklin Harbour Soil Pit Day.