Grain grower Zach McRae and his family are hosting a GRDC southern NSW farming systems trial to explore the value of adding more diversity to their farming system

Although Zach McRae and his family have grown faba beans on and off for the past 15 years, they have never known the actual value of the pulse to their farming system.

The 26-year-old crops 1457 hectares with his mother Julie and brothers Lewis and Joel near Urangeline, about 100 kilometres south-west of Wagga Wagga in southern New South Wales.

When replicated small-plot GRDC southern NSW farming systems experiments were set up on heavy brown vertosol soil near Urana in 2017, Zach, his family and their agronomist Heidi Gooden from Delta Agribusiness Lockhart joined many local growers as eager onlookers.

Small-plot work

GRDC, CSIRO and the NSW Department of Primary Industries and Regional Development (DPIRD) have co-invested in the small-plot farming systems experiments at Urana for the past seven years. From 2017 to 2023, the southern NSW farming systems project at Urana showed that a diverse, low-fertiliser nitrogen farming system incorporating faba beans produced the highest return on investment of all the crop sequences assessed (Table 1).

Project leader CSIRO Agriculture and Food chief research scientist Dr John Kirkegaard says GRDC extended and expanded the southern NSW farming systems project in 2024 to maintain the small-plot experiments into a third phase (2024–26).

“A new paddock-scale component called ‘Diverse Farms,’ led by Grassroots Agronomy, was included at six farm sites, comparing three-year sequences with four-year sequences running until 2027.”

Table 1: Findings of the Urana farming systems experiment 2017–23.

Other findings: On average, the faba beans (4.7t/ha at $522) made $210/year more profit than barley (6.2t/ha at $330/t). Significant grain yield benefits were made in the following canola (0.3t/ha) after the faba beans.

Source: Dr John Kirkegaard, CSIRO Agriculture and Food

Paddock-scale research

Diverse Farms explores the advantages and disadvantages growers experience when moving from a baseline canola/wheat/barley sequence to a more diverse farming sequence incorporating a pulse such as faba beans.

In partnership with Mrs Gooden, Zach and his family wanted to compare paddock-scale treatments comprising a three-year canola/wheat/barley rotation with a four-year rotation of faba beans/canola/wheat/barley.

“As a family business, we were interested in putting a dollar figure on the difference faba beans are making to our whole farm system,” Zach says.

Five other NSW growers from Jerilderie, Rannock, Thuddungra, Burcher and Tullamore are also participating.

Project takeaways

Mrs Gooden says the McRae family’s farm is only about 18km south-east of the GRDC southern NSW farming systems small-plot experiments at Urana, which NSW DPIRD’s Mat Dunn manages from Wagga Wagga.

“Even though the Diverse Farms trial on the McRae family’s property is on lighter soil than the heavy brown vertosols at the small-plot experiment at Urana, he and his family also have pockets of similar heavy soil types across their farm.

The outcomes of the small plot experiment at Urana are giving us confidence that including a pulse in the rotation is paying off across the whole farming system.”

Zach agrees, adding that until you try a pulse for yourself, it is not easy to judge their worth because every paddock and farm can be different. Faba beans comprise about 10 per cent of the McRae family’s cropping area. They grow faba beans before canola to lift mineral nitrogen and reduce the annual ryegrass population.

“Zach has a heavy focus on controlling ryegrass numbers in their faba beans,” Mrs Gooden says.

Whilst the double break provides excellent weed control, a secondary benefit often not realised is its positive effect on reducing cereal diseases such as crown rot.

Faba bean agronomy

In 2024, Zach set aside 88ha for the trial. Mr Dunn and his NSW DPIRD team surveyed the soil for pH, soil constraints and deep nitrogen to explore potential limits to production.

Mrs Gooden says the pH_Ca of the entire trial block averaged 5.3 in the top five centimetres, dropping back slightly to 5.1 at 5 to 10cm, then increasing with depth. This resulted from a variable-rate application of 1.3 tonnes/ha of lime.

On 7 April, the first pre-sowing knockdown was applied, which was a mix of Crucial® (glyphosate), Terrad’or® (tiafenacil) and CanDo® (adjuvant). Three days later, this was followed by a second knock of Gramoxone® (paraquat), Terbyne® Xtreme® (terbuthylazine) and Reflex® (fomesafen).

Faba bean inoculant

The Samira faba beans were inoculated with a double rate of the new acid-tolerant Group F rhizobia. The peat-based inoculant was put through the auger as the faba beans were loaded into the air seeder.

Each year, the McRae family has been edging its faba bean sowing time forward to grow more biomass and to lift the amount of nitrogen added to the soil profile.

On 11 April, they sowed 120kg/ha of Samira faba beans 50 millimetres deep into excellent surface moisture using a Flexi-Coil tyne and press wheel seeder set on 305mm row spacings. Eighty kilograms per hectare of diammonium phosphate (DAP) was applied at seeding.

Two days after sowing, a post-sowing Reflex® (fomesafen) was applied to manage annual ryegrass and volunteer cereals. The faba beans emerged on 20 April at an establishment rate of 40 plants per square metre.

Disease management

Mrs Gooden encourages a proactive approach to disease management, suggesting that fungicide applications are targeted to growth stages (specifically at the crop’s 4 to 6-leaf stage and, again, more significantly, at canopy closure).

On 11 June, the McRae family applied clethodim, Factor® (butroxydim), Veritas® Opti (azoxystrobin + tebuconazole) and CanDo® (adjuvant) to manage annual ryegrass, volunteer cereals and disease.

Six weeks later, on 21 July, this was followed by an application of Miravis® Star (fludioxonil + pydiflumetofen) to manage disease.

Mrs Gooden says monitoring during the season showed plenty of nodules around the roots with pink interiors, which is ideal for fixing nitrogen in the soil. “Our 2025 pre-sowing deep nitrogen tests will tell us how successful last year’s nodulation was.”

Harvest preparation

On 23 October, Crucial® (glyphosate) was applied as a pre-harvest tool. Three days later, Gramoxone® (paraquat) was applied to manage annual ryegrass and desiccate the crop.

Zach and his family harvested the faba beans on 18 November and stored them on the farm until a market was found.

The McRae family prefer to lock in a price after harvest and will hold the faba beans on-farm for up to 12 months to capture any market opportunities over this period.

“Faba beans tend to discolour if stored for more than 12 months. Also, heliothis can cause damage during pod fill if the insecticide timing is too late. Minor insect damage is okay if they are only intended for feed grade, but not if you want to sell them into the human consumption market,” Zach says.

“If they are sold into the export market, we deliver them to a packer near Melbourne. If they are feed grade, we sell them locally.”

The McRae family grew 2.3t/ha of export-quality faba beans on the Diverse Farms block in 2024. The total variable costs were $392.35/ha.

The family sold the beans for $660/t delivered to Melbourne, which equated to about $620/t on-farm. The gross return was $1488/ha, with a net profit of $1095.65.

Price risk

Zach says finding a reliable market can be difficult, making him cautious about expanding his faba bean area.

“We’ve sold faba beans for $770/t into Melbourne once, but they generally average $400 to $500/t, with prices sometimes as low as $200 to $300/t,” he says.

Mrs Gooden agrees, adding that while the GRDC southern NSW farming systems small-plot experiments at Urana have suggested there is production comfort in growing faba beans, this needs to be balanced with common sense.

It’s important to be flexible in your approach to the number of hectares of faba beans you plant each year.

“While there are benefits to planting faba beans, the McRae family likes to reduce potential downside price risk through a conservative approach to the area they sow each year” she says.

Barley agronomy

The McRae family also plants 10 per cent of the farm to barley, diversifying their production and marketing risk.

“Barley seems to handle frost better than wheat and always seems to yield well when conditions turn dry,” Zach says.

To control annual ryegrass, sow thistle and wild oats before sowing in 2024, Voraxor® (saflufenacil + trifludimoxazin), Crucial® (glyphosate) and CanDo® (adjuvant) were applied on 2 May 2024.

After a light burn to parts of the paddock to reduce the wheat residue, on 8 May, the McRae family sowed 50kg/ha of Maximus CL barley into moisture with drying surface conditions. The barley was treated with Systiva® (fluxapyroxad) to control seed and soil-borne diseases. Eighty kilograms per hectare of DAP was applied at sowing.

The crop emerged on 19 May. On 1 June, the block was top-dressed with 160kg/ha of urea.

Two months later, on 2 August, Intervix® (imazamox + imazapyr), LVE MCPA (2-methyl-4-chlorphenoxyacetic acid), Lontrel® Advanced (clopyralid) and CanDo® (adjuvant) were applied to the crop.

On 14 November, the barley was harvested and yielded 5.9t/ha. At the time of writing, only one load of the barley had sold and, pleasingly, made malt quality.

The remainder, awaiting sale and stored on the farm in bags, is also expected to make malt. The total variable cost of production for the barley was $418.05/ha.

While the McRae family is yet to sell their barley, Dr Kirkegaard says the small-plot experiments at Urana showed that faba beans (at 4.7t/ha at $522/t) made $210/ha/year more profit on average than barley (6.2t/ha at $330/t) over six years.

He says there were also significant grain yield benefits in the following canola (0.3t/ha) after the faba beans.

“A single-year comparison between faba beans and barley is not the point of the Diverse Farms paddock-scale trials,” he says.

“Comparing the sequence profits and picking up the value of the legacy effects shows faba beans can be a profitable addition.”

CSIRO Agriculture and Food chief research scientist Dr John Kirkegaard. Photo: Nicole Baxter

Crops for 2025

For 2025, the McRae family has earmarked Optimum Gly® PY525G canola to be planted into the faba bean and barley stubble to explore the effects of its 2024 management on yield, oil, weeds, pests, diseases, water use and finances over the two-year sequence and, ultimately, across four years.

NSW DPIRD will continue to take deep soil samples yearly to determine the amount and location of residual nitrogen and refine the fertiliser strategy on each block.

Zach says he continues to be inspired by the team helping to ground-truth the role of faba beans on his family’s farm.

We want to make sure that the long-term benefits of faba beans outweigh the more conservative approach we have had in the past to give us the confidence to grow faba beans more consistently.

Mrs Gooden says she was excited by the more than 35 growers and advisers who attended the Diverse Farms paddock walk at Zach’s family farm in September 2024.

“A high percentage of growers who came along to the Urangeline field day in 2024 were already growing legumes but were all looking for ways to improve what they do, which was encouraging.”

Look for Grassroots Agronomy social media posts on future Diverse Farms paddock walks.

More information: Zach McRae, jjmcrae@bigpond.com; Heidi Gooden, hgooden@deltaag.com.au

Read more in GroundCover^TM story Difficult finish highlights diversity's value.

GRDC Update Paper – Farming systems profit and risk over time: exploring the N legacy impacts on profit in different farming systems.