‘Well sown is half grown” is the mantra of South Australian cropping farmer Tom Robinson when it comes to successful seed establishment under a no-till regime.
Ahead of presenting at a conservation agriculture global forum, Robinson addressed a Foundation for Arable Research Growers Leading Change webinar, during which he shared with New Zealand his journey to building healthier soils.
Robinson farms at Hoyleton, South Australia, with his partner Cassi and his parents Ashley and Kaylene.
The 1500ha property grows wheat, barley, canola, peas and lentils. Because of the hot dry summers, they normally only grow spring crops over mild winters.
Robinson said the four key principles of zero-till disc seeding – cut, place, press and cover – have been the biggest change on the family farm for 160 years.
With minimum till for 12 years, the farm ran no livestock for 28 years and has now been zero till for 25 years.
The early years of no-till focused on retaining as much residue on the soil surface as possible for moisture conservation in their hot, dry climate.
They later realised the additional soil health gains.
“Perfect seed placement for every seed in every row across the whole farm is our goal.
“Every seed costs dollars to put in the ground so drill set-up and placement absolutely matters,” Robinson said.
The implementation of a Shelbourne stripper header has helped to retain as much stubble as possible, while also increasing water-holding capacity.
In more recent years a controlled traffic system has been established to keep all the machinery on the same wheel tracks.
“Controlling our traffic lets us control where our soil compaction happens.”
The farm’s 325-425mm annual rainfall happens predominately in the winter. In the summer it bakes with temperatures above 40degC and annual evapotranspiration of 3000mm.
A lack of moisture is the biggest limiting factor. The benefits of moisture conservation mean that average wheat yields are 4t per hectare no till and full input, with double that achieved under full tillage and full input.
“We started playing with summer cover crops between our winter cropping system and also started to grow massive winter cover crops, and trying to grow summer crops like sunflowers, mungbeans, millet and corn through our hot dry summers.
“We like sunflowers, they don’t have much ground coverage, but they have a big taproot and are hardy in our hot summers.”
Tillage radish sown through the standing harvested crop is grown for livestock.
“We had no livestock for 28 years, well Dad had a sheep stud before that, but when I came in we were full cropping.
“My wife wanted some cattle, she wanted one, I said, ‘Have one, have 100’, so that’s where livestock came back in 2018.”
Robinson’s innovative practices have significantly improved soil health and productivity.
The multi-species companion and cover crops are improving soil productivity and farmgate returns while reducing farm inputs.
As well as his early experience with increasing plant diversity, Robinson’s ability to modify machinery to meet farmer needs has hastened adoption of the dryland farming system in his region.
A key factor in establishing diversified crops has been the ability to retain standing stubble, optimising seed placement and crop establishment by using a zero-till disc on 6-inch row spacings.
Operational and fuel efficiency has been improved via the 3m permanent wheel tracks, which have reduced the area of paddock compacted by farming machinery.
All these practices have increased water infiltration and efficiency.
The farm’s ability to maintain soil cover and reduce soil compaction has reduced the risk of soil erosion and water runoff and increased soil pore space and organic matter content.
Increased plant diversity has increased the number of beneficial species, thereby reducing the need for pesticides and pollination services.
Robinson has increased his understanding of land management practices through interacting with leading farmers and researchers, including several trips abroad.
Over the years he has presented at the No-Till Conference in Kansas, the Colorado Conservation Tillage Association and at the Conservation Agriculture Conference in Cape Town, South Africa.
He has also worked closely with South Australia’s Department for Environment and Water to improve his understanding of soil microbiology and with the South Australian No-Till Farmers Association as a board member and chair.
“It’s all about the social licence of farming and how that is perceived by the public.
“The question is, How do you want to farm and look after the soil and preserve it for future generations?”
Robinson recommends that farmers adopting no-till terminate a cover crop three to four weeks before seeding, leaving an unsprayed test strip to see whether this will work in their own situation.
“We find the material breaks down fairly quickly. That’s where trial work is needed on your own farm.”
