Snapshot

Grower: Robin Schaefer 
Location: "Bulla Burra" Loxton, South Australia
Farm size: 8,500 Ha 
Enterprise: Continuous cropping
Growing season rainfall: 275mm annual and 175mm growing season
Soil type: Highly varied - deep sandy rises, loamy sands, sandy loam flats, areas of shallow calcareous stone and heavier clay loams with subsoil constraints.
Cropping program: 66% cereal and 33% pulses
Seeding system: No-till farming, 3m centres, 12.2m seeder and 36.6m, boom width - self propelled and WEEDit.

Robin Schaefer is the general manager of Bulla Burra, an 8,500 Ha cropping enterprise at Loxton and Alawoona in the South Australian Mallee. Bulla Burra is known to experience challenging seasons and highly variable growing season rainfall, ranging from 60mm to 325mm.

They focus on innovative approaches to soil protection and managing erosion, which has been highly beneficial and a significant driver in their crop production increases. However, Robin will testify to times when they haven’t always got it right, and paddocks have blown, yet they have put these situations down to experience.

Soils across Bulla Burra’s farms vary from deep sandy rises and loamy sands through to sandy loam flats, interspersed with areas of shallow calcareous stone and heavier clay loams with high subsoil constraints.

The continuous cropping, controlled traffic, no-till farming system comprises approximately 66% cereal (wheat and barley) and 33% pulses (peas, lentils, chickpeas and lupins). There is no livestock within the system, and they believe this greatly increases their ability to control erosion risks and maintain soil cover, particularly on fragile sandhills.

All machinery is set up on 3m wide tracks with seeding, rolling, and harvest equipment set to 12.2m widths. Bulla Burra uses 36.6m self-propelled boom sprays with WEEDit optical sensor capacity.

Sowing crops by the calendar and not according to moisture status!

Sowing all crops, including pulses, by the calendar allows for excellent rotational and operational efficiency benefits.

For Bulla Burra, maintaining adequate soil cover is the absolute key to a sustainable continuous cropping system. Sowing their planned rotations by the calendar, rather than being dramatically altered by late breaks or little stored moisture, enables them to maximise production each season.

Robin has learnt that sticking to their plans, including dry sowing pulses, is easier as in-season rotation changes impact the business’ longer-term rotational plans. Sticking to the plan also provides greater operational efficiencies.

Over the years, Robin has found that pulse crops are very resilient. Even in poorer seasons, they provide significant rotation benefits for weed and disease control while still contributing some nitrogen for the following cereal crop and often a positive gross margin.

However, Robin stresses that farmers need to grow their confidence in taking this approach on a few paddocks, and make sure that their whole system is in place for it, rather than dry sowing just as a last resort.

One size doesn’t fit all when it comes to pulse sowing windows

Pulses at Bulla Burra are always sown within optimal sowing windows, and according to soil type zones, to optimise seasonal production. Typically, this includes:

• Field Peas - Grown on sandier soils and into heavy cereal stubbles, sown after the 20th of May to assist frost mitigation.
• Lentils – Generally grown on loamier soils and sown in the first few weeks of May.
• Chickpeas – Whilst drought resilient, they are used less frequently to minimise disease carry-over and fungicide application requirements. Often sown mid-April to the first week of May.
• Lupins – Grown on their southern deeper sands where free lime is not an issue. Their flexible sowing windows are used depending on where needed and the flow of the sowing program.

They keep getting better

Robin has found the more they grow pulses, the better they get, due to the cumulative pulse inoculum carry-over, even in sandy soils.

Pulses have become a critical component of the Bulla Burra rotation. In 2021, a very dry year, lentils produced gross margins equal to the best cereals, and this was off no subsoil moisture, a 13mm break which came in June and a total growing season rainfall of 137mm.

“As we have learnt how to grow pulses in our environment, through a gradual paddock by paddock system approach, we now have the confidence to dry sow them by the calendar and on minimal stored moisture," he says.

Maintaining anchored soil cover at all times

Retaining anchored soil cover from the cereal phase and within in the pulse year, is the key to confidently managing pulses through drought periods.

Considering tractor and equipment passes across paddocks is critical in ensuring ground cover maintenance. Bulla Burra’s matched width equipment allows them to strategically seed, roll and harvest pulse crops in exactly the same direction on their AB lines to best retain anchored cereal stubble, reducing standing stubble breakage.

Robin and his team are conscious of potential rolling damage on deep sands, especially on deep ripped areas. The soft sand can cause a “bow wave” in front of the roller, burying the plants and stubble. Crop loss in these areas can lead to erosion over summer, so sandy rises are often left unrolled.

On Bulla Burra’s most vulnerable sands, they use the third bin on their air cart to sow cereal (wheat or barley) at about 10kg/ha with their pulse crops to increase early ground cover growth. The timing of cereal removal with selective grass applications is seasonally dependent. In some areas and/or in tough years, it may be left to grow through to assist soil protection. Maintaining anchored soil cover is a priority in buffering against future erosion risks.

Controlled Traffic Wheel Track Safety Strategies

Keep machine traffic over deep sands safe.

Robin believes controlled traffic is vital in achieving excellent crop growth, improving traction and fuel efficiencies and reducing paddock compaction. However, wheel tracks created over vulnerable soils remain a constant challenge, with the potential to become catalysts for blowouts.

Bulla Burra manages this by switching tramlines for their in and out of season passes. This creates additional challenges as partial spray strips, headlands and fence lines require careful management, although it is well worth the effort, particularly through extended drought periods.

For any wheel track areas which start to blow, Robin has found tractor blading in the autumn before sowing to deliver the best results. Even small unattended areas with poorer crop establishment and crop growth have the potential to blow and increase in severity over the following year.

Robin has also indicated he is considering chaff lining within wheel rows, even if it is only done in certain cereal years, as this could greatly enhance the soil protection in these areas.

Safe strategies for farmers not dry sowing pulses by calendar

Brenton Schober also farms in the SA northern Mallee and hesitates to dry sow pulses in his operation. “If we have good stored moisture from summer then we have the confidence to sow a lot drier,” he says. However, in areas most vulnerable to wind erosion, he will only sow after rain.

• Going into a season with good moisture and stubble cover, Brenton will grow chickpeas, as they are easier to harvest and perform well on sand. They need to be sown before mid-May, as they can be very slow to establish.
• When there is less cover and late rain, peas will be sown, but not until mid-May due to their high frost susceptibility. Peas will not be sown after the first week in June if no rain has fallen. Instead, Brenton will leave the paddock out to chemical fallow in preparation for the following season, or possibly sow a Clearfield barley if a good rain comes in June. This helps to maximise his chances of containing problem weeds and establish cover while still maintaining the possibility of harvesting a profitable crop.
• Following a poor season where erosion prone sandhills are left with inadequate protection, the Schobers will broadcast cereal seed prior to sowing their pulse crop. This cereal germinates with the pulse, providing soil cover through establishment. Depending on the season, the cereal can be removed with a grass spray, or left if the season is dry.

Read more: Brenton repairs erosion ‘blowouts’.