Snapshot

Owners: Tom and Greg Bell
Location: Millicent, South Australia, and Narromine, New South Wales
Area: 2500 hectares cropping and 1300ha non-arable at Millicent, 3350ha cropping at Narromine
Average annual rainfall: 750 millimetres
Soil types: heavy black clay flats, with some peat and loamy soils
Soil pH range: 7.0 to 9.0
Crops: wheat, canola, broad beans, clover seed
Enterprises: cropping and sheep for prime lamb production

Grower-driven research is helping grain growers in one of South Australia’s smallest cropping regions close the gap between actual and potential yields.

The results can be seen in the award-winning wheat crop produced by mixed farmer Tom Bell, which won both of the state’s prizes in the second annual GRDC Hyper Yielding Crops initiative, announced in August.

Tom, who farms with his wife Lucy, father Greg and a team of valued workers at Emerald Farms near Millicent in the state’s south-eastern corner, harvested 11.48 tonnes per hectare of RGT Accroc wheat in January.

Not only was it the highest-yielding wheat crop  in SA, the dryland crop returned 109.33 per cent of its potential yield, which had been estimated at 10.5t/ha.

As members of the MacKillop Farm Management Group, Greg and Tom were among a group of growers from the Limestone Coast watching with interest the work being done in Tasmania by FAR Australia.

“Our environment is more like parts of Tasmania, New Zealand or Europe. It’s totally different to the Mallee or the Mid North of South Australia, for example,” Tom says.

“A few of us travelled down to Tasmania to see the hyper-yielding site. From there, we got together and – with support from Landmark as the major sponsor – we had a pilot trial site for a year.”

They lobbied GRDC to invest in research, development and extension to increase yields and realise the potential of grain production across the high-rainfall zones on the mainland. This led to the establishment of the GRDC and FAR Australia SA Crop Technology Centre, near Millicent.

“It’s been a really good thing,” Tom says. “The varieties that we’ve been getting access to out of France and the UK have helped, but having sites like this has enabled us to try and refine fungicide, growth regulator and fertiliser use for these better varieties and push yields.”

So how did he do it? Preparation of the paddock, which had been used for canola the previous year and broad beans in 2019, began with spreading single superphosphate across the short stubble at 125 kilograms/ha.

General practice is to undertake a first pass with a Grizzly Tiny equipped with 750-millimetre offset discs and a crumble roller, followed by a second pass with a Horsch Speed Tiller to tidy up and level off the field.

“We don’t burn our stubbles,” Tom says. “We cut very low to the ground to help the breakdown process of heavy stubble loads. There’s a lot of organic matter that holds the soil together, which gives good structure and nutrition. Not burning it and ploughing all the stubble back in helps maintain the productivity and sustainability of the system.”

Tom Bell and family in a wheat crop. From left: Daisy, Lucy, Harriet and Tom. Photo: Brad Collis

Roundup at 2.5 litres/ha and LVE-Polo at 400 millilitres/ha were applied as a knockdown to manage mainly volunteer canola, charlock and ryegrass ahead of sowing.

The RGT Accroc wheat was sown on 14 May 2021 at a seeding rate of 150kg/ha using an 18-metre Flexi-Coil airseeder equipped with tynes on 229mm row spacings.

Tom had treated the seed with Gaucho to control aphids, which spread barley yellow dwarf virus – a disease that can substantially reduce yields.

It was sown with starter fertiliser of monoammonium phosphate at 140kg/ha, and a pre-emergent herbicide mix of Avadex and Sakura was applied for early season control of ryegrass and other weeds.

The seeding rate was higher than the usual 120kg/ha because it was intended for grazing.

As well as continuously cropping 2500ha of mostly heavy black clay flats, with some peat and loamy soils, the Bells run about 7000 ewes and 2000 ewe lambs. The breeding flock is a mix of Border Leicester-Merino first-cross ewes and Primeline composite ewes.

The sheep graze on pastures of Holdfast GT phalaris, ryegrass and Persian, Palestine and balansa clover, but also forage on crops and stubble when pasture needs to be rested or growth stalls in winter.

Post-seeding, the wheat crop was top-dressed four times, with applications of either straight urea or a urea/sulphate of ammonia blend, providing a total of 203kg/ha of nitrogen for the season.

It also received sprays of the insecticide Strike-Out in July to guard against aphids, and the fungicides Prosaro, Aviator and Avior Gold at growth stages 32, 39 and 65.

We got our timings right, as well as higher levels of solar radiation while still having mild temperatures through the critical spring period.

Regular significant rain events from late May to August included the wettest July on record and contributed to 620mm of growing-season rainfall. Rainfall for 2021 totalled 740mm, just shy of the annual average of 750mm.

“It was borderline too wet in winter,” Tom says. “We were out there clearing surface water with excavators, not in every paddock, but there was water laying around. A lot of our country’s got a drainage system that was set up years ago when it was developed, and all the surface water eventually goes out to sea through big drainage channels.

“So we’ve got the drains in place for when things do get wet, which does help but doesn’t totally eliminate the effects of waterlogging.”

After deciding not to graze the crop because of the wet conditions, Tom applied a blend of the plant growth regulators Moddus Evo at 200ml/ha and Errex at 1.25l/ha in August at GS32 to reduce the risk of lodging and improve efficiency when it was harvested on 20 January.

Mild spring temperatures and timely rainfall were beneficial for flowering and grain fill.

“The main thing was we got our timings right, as well as higher levels of solar radiation while still having mild temperatures through the critical spring period,” he says.

“It wasn’t really much different to what we normally do, to be honest. Some of the wheat we graze, some we don’t. But we’re really conscious of our phosphorus levels. And we’ve increased our fertiliser inputs to maintain nutrient levels, because we know the higher yields are removing more nutrients and good nutrition is critical to our yields.”

Tom’s result was no fluke – wheat yields at the SA Crop Technology Centre exceeded 12t/ha for the first time on the mainland in early sown trials of three varieties last season.

As well as producing wheat for grazing, hay and grain, the Bells grow broad beans, which are exported to the Middle East where they are a popular source of protein for human consumption. They also grow canola and small seed crops, such as balansa clover seed.

The rotation is usually broad beans followed by canola, then wheat, and the occasional wheat/wheat crop.

Potential for better canola yields

As much as the record wheat crop was nice to tick off, Tom says he is even more excited by the potential for better and more-reliable canola yields, which averaged 4.8t/ha last season and returned a similar gross margin to a 10t/ha wheat crop.

“We’re growing all winter canola varieties – Hyola Feast CL, Phoenix CL and Hyola 970 CL,” he says. “They almost lay dormant in the winter, which delays their development and allows them to survive when the crops are under water. Similar to our winter wheats, they can really handle prolonged waterlogging, which is a major challenge here.”

This year’s wheat crops are the winter varieties RGT Accroc, RGT Cesario and Big Red, and the spring type RockStar .

Tom prefers growing mostly red feed wheats because they consistently outyield white milling varieties.

“We probably can’t get the white wheat to yield as well as we can our reds,” he says. “For example, if we can get an extra 2t/ha on our red wheat, we’re still in front even if we were to get, let’s say, a $50/t premium for white wheat that goes APW.”

The main problem weed is ryegrass, and the Bells are careful to rotate chemistry and cut cereal paddocks for hay to reduce the risk of herbicide resistance.

Tom says they usually cut quite a lot of hay, generally “the dirtier paddocks”, but it depends on supply and demand and whether the price stacks up against grain.

A small portion of the hay is used within the business, but most is sold to livestock producers and dairy farmers within a few hundred kilometres of the farm.

MacKillop Farm Management Group Hyper Yielding Crop project officer Jen Lillecrapp says growers have made substantial investment in infrastructure and machinery in the past 20 years.

“They are committed to producing grain and we are a reliable producer of grain. When you look back at the big droughts in recent times, large areas of the more-traditional but marginal areas were not able to produce much grain. However, the high-rainfall districts were able to consistently produce grain,” Ms Lillecrapp says.

“The high-rainfall areas are critically important for the rest of the country in times of drought. The national average wheat yield is about 1.8t/ha. We can grow five times that per hectare, so from only relatively small areas we are able to reliably produce significant tonnes, which are especially critical for the increasing intensive livestock industries.”