Canola is booming in Western Australia as growers are attracted to the crop’s economics; the trick now is to find the right balance to maintain the agronomic benefits of pulses.
- Field pea plantings have fallen while canola plantings have tripled in the past four years
- Field peas offer agronomic and other benefits, including increased soil nitrogen, alternative integrated weed management options and, in subsequent wheat crops, increased yield and protein levels
It is a simple philosophy – do something every year that will improve the farm – and it works well for south-east Western Australian grower Ron Longbottom. “We are looking at slow improvements. Our philosophy is ‘adapt’,” he says.
Farm owners: Ron and Kerrie Longbottom
Farm manager: Ron Longbottom
Location: Grass Patch, Western Australia (85 kilometres north of Esperance)
Farm size: 6400 hectares of arable land, 800ha of tree lines and scrub
Rainfall: 350 millimetres annually (a third falling in summer and the rest in winter)
Soil type: sodic soil
Soil pH: 7 to 8.5
Like many WA growers, Ron, who farms with his wife Kerrie and full-time employee Farney Rossouw at Grass Patch, 85 kilometres north of Esperance, is looking at how he can “tweak” his wheat-and-field-pea-based rotation by including more canola. He is experimenting with both the rotation mix and canola varieties.
It is a scenario familiar to Pulse Australia’s industry development manager in WA, Alan Meldrum. Mr Meldrum has seen the area planted to field peas in the state drop by 50 per cent in the past three years, while canola plantings continue to grow.
“About 1.3 million hectares of canola have been planted this year, more than three times that of just four years ago,” he says.
Mr Meldrum says field peas, along with lupins, have been under pressure from canola for a few years, mostly due to the oilseed’s profitability – gross margins up to $150 per hectare more than for field peas – plus there is easier market access.
“Both triazine-tolerant and GM canola offer a range of marketing options, including forward contracts, futures and a very stable price outlook.
“To export field peas you need to find a buyer, secure payment guarantees and then ship the grain – a harder task for those in the Esperance region where there is only a small quantity of field pea to market.”
Growers are also turning to canola for the weed-control options it offers: “Triazine-tolerant canola has a wider range of in-crop herbicides than the pulses and this scenario is true for most of western and southern Australia.”
Yet, despite canola offering a higher return per hectare and more marketing and weed-control options, Mr Meldrum and growers such as Ron Longbottom are quick to point out that field peas still have a crucial role to play in a balanced cropping regime.
Ron says the crop’s contribution to high soil nutrition lifts the yields of subsequent cereal crops. For example, wheat planted on field-pea stubble in 2013 yielded 700 kilograms/ha more than wheat planted on canola stubble.
Ron Longbottom is pondering how he can tweak his wheat-and-field-pea-based rotation by including more canola without losing the agronomic benefit of pulses.
PHOTO: Evan Collis
As well as this yield boost, Ron says field peas also contribute to integrated weed management (IWM) and nematode control.
He explains that, for him, field peas are well suited to crop topping – the control option for annual ryegrass where a desiccant herbicide is applied close to the pulse’s final maturity. For growers in the Esperance region this usually occurs in October.
Mr Meldrum says as field peas are close to maturity when the herbicide is applied, yield and grain quality risks are minimised.
The ideal timing for crop topping is when the field pea seeds have reached 30 per cent moisture, or when the lower 75 per cent of pods are brown with firm seeds and leathery pods.
“A good result is about 80 per cent control of ryegrass seed set with little damage to the pulse. This can be less, depending on weather and regrowth; however, early harvest and capture and removal of weed seeds from the paddock can combine to give an overall ryegrass control of up to 95 per cent.”
Mr Meldrum says crop topping also targets resistant weeds, but he stresses that it only works as part of an IWM plan in which the herbicide label’s withholding period is strictly adhered to.
So the decision for growers at the moment is how to balance the pros and cons of canola and field peas in a rotation. Mr Meldrum suggests an extended rotation: perhaps introducing field peas to a paddock every five years instead of every three or four.
He says Pulse Australia is writing a manual on growing field peas to help growers understand the dynamics of field pea agronomy to make decisions on including them in the rotation clearer.
The manual will show how to avoid diseases such as blackspot and improve harvesting efficiencies. “Field peas tend to lodge at harvest so the process is slower than with other crops.” Experienced growers already have this in hand, but Mr Meldrum is keen, despite the strong competition from canola, to help new field pea growers make the crop a success.
As Ron contemplates changes to his rotation, he says it all comes down to what is good for a paddock in the long term.
“And for us, that will be to continue with field peas.”
Field peas can break the nematode cycle
Work by the Department of Agriculture and Food, Western Australia (DAFWA), is showing that field peas can help manage root lesion nematodes (RLN).
DAFWA development officer Greg Shea says field peas are an excellent break crop for RLN because they are moderately resistant to the nematodes. “This means there is a lower multiplication rate of the nematodes where field peas are included in the rotation compared to susceptible crops such as wheat.”
He says the incidence of RLN – microscopic worm-like animals that feed on plant roots, often causing damage that can result in yield loss, particularly in susceptible crops such as wheat and canola – was high in 2013.
Work through the Focus Paddock project has identified a worsening trend since 2010, which could be due to seasons favouring RLN multiplication where susceptible crops are sown.
“In 2010, 184 paddocks were monitored and 46 per cent of the sites tested negative to this nematode. This has reduced to 32 per cent of samples taken in 2013.”
Mr Shea says 2014’s early break to the season gave growers an opportunity to include field peas in their program.
0428 757 040
0427 384 760
Rusty grain beetle tests storage defences
Inoculants need knowledge and tactics