Rising interest in the potential farming system benefits of faba beans saw 75 growers and agronomists attracted to a focus session at Ganmain in southern New South Wales in March.
For the past three years, Brill Ag, with collaboration from Field Applied Research (FAR) Australia, Grain Orana Alliance, Ag Grow Agronomy and Research and Frontier Farming Systems – with GRDC investment – has shown the value of legumes in trials across southern and central NSW.
The work is part of the GRDC Pulse Agronomy project, which runs across NSW (led by Brill Ag), South Australia (led by the South Australian Research and Development Institute), and Victoria (led by Agriculture Victoria).
GRDC grower relations manager – north Graeme Sandral told growers and agronomists that faba beans were an excellent rotation crop. Photo: Nicole Baxter
At the Ganmain event, GRDC grower relations manager – north Graeme Sandral said faba beans could generate high returns while boosting soil nitrogen, decreasing the weed burden and reducing yield losses from cereal diseases.
“A double break is very effective at reducing crown rot while beans allow active ingredients like butroxydim (Factor®) to be used for annual ryegrass control,” he said.
Given these benefits, he encouraged growers and agronomists to calculate a gross margin for faba beans across a four-year rotation to better reflect their value to the farming system rather than as a one-year cash crop.
Middle Eastern countries are the major buyers of faba beans for soups and casseroles, roasted as snacks, or milled into flour. In the domestic market, traders source faba beans for intensive pig and poultry rations.
Faba bean scorecard
Brill Ag research agronomist Rohan Brill said faba beans scored highly when compared to other grain legumes (Table 1).
Table 1: Pulse comparison (1 = best, 5 = worst).
Variable soil: The ability to handle soil from well-drained loam soil to sodic and poorly drained soils. The main limitation of faba beans is their inability to tolerate soil acidity.
Nitrogen fixation: Is related to biomass production. Faba beans had the highest nitrogen fi xation in wetter years and average nitrogen fixation in drier years. Lentils and chickpeas generally produced lower biomass.
Sowing logistics: Seed volume and ability to handle seed in air seeders.
Harvest: Ease of harvest and whether specialty equipment is required.
Cost: The cost to grow, which includes seed, fungicide and application.
Grass control: Includes herbicide options pre and post-emergence, as well as competitiveness and maturity timing to allow crop topping.
Broadleaf weed control: Includes herbicide options pre and post-emergence, as well as competitiveness and maturity timing to allow crop topping.
Disease management: Ability to control disease in crops.
Rotation: Benefits for following crops. For example, nitrogen fi xation and weed control but also reduce the buildup of diseases including root lesion nematodes and Sclerotinia.
Source: Rohan Brill, Brill Ag
He said faba beans were the standout pulse crop across southern and central NSW Pulse Agronomy sites in 2021 and 2022, producing the highest biomass and fixing the highest amount of nitrogen into the soil.
“Correctly inoculated pulse crops host symbiotic rhizobia that convert atmospheric nitrogen into plant-available nitrogen. A rule of thumb in Australian agriculture is that for every tonne of above-ground pulse biomass, 20 kilograms per hectare of nitrogen is fixed by rhizobia.”
However, Mr Brill said recent research in southern and central NSW had shown that this underestimated pulse crops’ nitrogen contributions.
In 2021, 2022 and
“Our research has shown that when below-ground nitrogen is accounted for, the total nitrogen fixed averaged about 30kg/ha,” he said.
“Therefore, we must factor in the below-ground nitrogen contributions when considering adding pulses to our farming systems because our research shows their overall benefit may be more than what is often assumed.”
He said faba beans, field peas, lentils, lupins and vetch had published root factor values of 1.5, meaning that for every 1kg of atmospheric-derived nitrogen in the above-ground biomass, there is an extra 0.5kg of fixed nitrogen below ground. For chickpeas, a value of 2.0 is used.
Grain yields
Mr Brill’s research with his collaborators demonstrated that faba beans were high yielding and fixed large amounts of nitrogen.
“In 2021 and 2022, faba beans outyielded all other pulses at 4.8 tonnes per hectare on average across all the sites (data not shown) and added 194kg/ha of nitrogen after accounting for nitrogen removal in grain, which was more than all other pulses,” he said.
To calculate the total value of a faba bean crop in simple terms, Mr Brill used the equation:
Faba bean crop value in dollars per hectare =
(Grain yield in tonnes per hectare x Grain price in tonnes per hectare)+(Nitrogen benefit in kilograms per hectare x Nitrogen price in dollars per kilogram)
“It is likely that when nitrogen costs are high and faba bean prices are modest, faba beans would still be competitive with most other crops in a gross margin comparison,” he said.
“For example, when faba beans are valued at $360/t on-farm, faba beans yield 4t/ha and nitrogen costs $2/kg when the nitrogen benefit is 194kg/ha, the gross income is $1828/ha.”
$1828=(4 x 360)+(194 x 2)
He said this roughly equated to the gross income of a 5t/ha Australian Premium White (APW) wheat crop but with the added benefits of improved weed and disease control.
“In reality, pulses should not compete with cereals and oilseeds for cropping area but rather should complement their production as part of a system.”
Latest results
In 2023, Brill Ag trial results showed PBA Nasma faba beans produced 2.9t/ha of grain and 12.4t/ha of biomass at Caragabal and 2.1t/ha of grain and 8.9t/ha of biomass at Ganmain (Table 2).
Table 2: Top treatments 2023 according to New South Wales location.
Source: Rohan Brill, Brill Ag
“The northern faba bean variety PBA Nasma performed well when yield potential was set up and spring conditions turned dry,” Mr Brill said. “Chickpeas also performed well in the dry finish.”
On average, he said CBA Captain chickpeas produced $1352/ha of grain and fixed 195kg/ha of nitrogen. However, PBA Nasma produced $998/ha of grain and fixed the highest nitrogen (260kg/ha) of all the legume species screened (data not shown).
Plant density
Overall, Mr Brill said trial results showed 20 plants per square metre were optimal for grain yield. He said grain weight must be considered when targeting sowing rates (Figure 1).
Figure 1: Target seeding rate (kg/ha).
Source: Rohan Brill, Brill Ag
“If you want 20 plants/m2, you might have to target a sowing rate of up to 160kg/ha for varieties like PBA Amberley, according to seed size,” Mr Brill said.
“But FBA Ayla might need to be sown at up to 120kg/ha, with PBA Nasma and PBA Samira at up to 145kg/ha.”
Sowing date
Mr Brill said PBA Samira could be sown mid-to-late April, with PBA Nasma sown in late April, depending on seasonal conditions.
“You can reduce disease pressure by not sowing too early,” he said. “But if the spring is dry, grain yield can suffer if faba beans are sown late.”
He said PBA Amberley was suited to sowing in NSW’s eastern high-rainfall areas because it had superior chocolate spot resistance.
“PBA Samira was suited to medium-rainfall areas,” he said. “And PBA Nasma and FBA Ayla were suited to low-to-medium-rainfall environments.”
Rotation benefits
Mr Brill said PREDICTA® B tests completed pre-sowing in 2023 on the Ganmain 2022 pulse site demonstrated the value of faba beans as a legume crop in rotation with canola and cereals.
“Faba beans had a low number of Pratylenchus thornei per gram of soil (0.7/g) compared with both chickpeas and vetch, which had numbers above threshold levels for yield loss of wheat.
“There was also a low level of Sclerotinia (48,000 DNA copies/g soil) after faba beans compared with other pulses, especially lentils (5,073,000 DNA copies/g soil).
“The PREDICTA® B test is still under development but clearly highlighted the differences between species.”
More information: Rohan Brill, rohan@brillag.com.au