Using compost to create a 10% increase in wheat yield


July 2021

An Australian Soil Management project on the Riverina district cropping farm of Brendan Pattison is showing accelerated results, with a 10% wheat yield increase and a protein increase in the first year.

This was achieved in the farm’s first cropping season with zero synthetic inputs.

The Pattison’s are one of five farmers trialling compost for Australian Soil Management through an active carbon farming grant.

Brendan farms with his wife Felicity and three children, and his parents John and Michelle at Marrar.

He is one of the district’s early adopters of soil-biology focused farming. The 1500ha property of undulating red loam with granite and quartz rises has been under a minimal input soil biology system since 2007 when they started moving towards zero-till.

They’ve tweaked the system along the way for the dual benefit of improving soil quality without compromising profitability.

They first transitioned from prime lamb and cropping to 100% cropping in 2014. In 2017 they introduced trade cattle to boost soil biology. In 2019 they moved back to 100% cropping and will trade cattle when market conditions align.

After visiting other project participants, Brendan says he was keen to see how compost might play a role in stimulating his soil biology in his non-conventional system.

“I love seeing what others are doing on their farms, and this project is a great opportunity for me to see how it can work on my farm. I’m not in a mad rush, I’m in this system for the long haul.”

For the 2020 growing season, good soil structure and nutrient cycling gave Brendan the confidence to reduce nitrogen inputs across the whole farm, using only biological inputs to stimulate plant growth.

He did a baseline soil test in March 2020, then another in September. He says this data indicates the compost is already providing benefits in soil quality.

“It’s really encouraging to see what’s happening already, it shows that our system is primed and ready for the compost to do its thing. We’ll be watching what certain trace element numbers do over the next couple of years as the compost breaks down and cycles.”

Brendan spread the compost in a paddock that he says has come ‘leaps and bounds’ after 10 years of changed management including reduced synthetic inputs, plant diversity and zero-till.

“I wanted to do the trial in a strong paddock, where I’ve been winding back inputs and which has still been producing grain, even in dry years.”

Brendan says just using biological inputs meant the wheat didn’t look and grow as vigorously as it would with synthetic inputs but it ‘caught up’ at the back end of spring. He says the wheat under compost performed even better.

“Having a yield increase and a protein increase in that grain as well was very positive to see. Although we’re still waiting on data, what data we do have also shows there’s been a benefit in soil quality.”

It’s the first time he has used compost and says he will monitor closely for extra biological activity over the next couple of years.

“Compost is another link in the chain in our system and I’m keen to see what happens in another 12 months. Our focus is looking after our biology and promoting more biology, and we’re really interested in exploring compost as another avenue for improving soil health and providing nutrition for a crop.”

  • The ASM Active Carbon Project grant is a Waste Less Recycle More initiative funded from the waste levy.