Oats were part of a suite of dual-purpose cereal varieties investigated for their fit in the non-traditional, high-rainfall grain region of north-eastern New South Wales.

Included in the NSW Department of Primary Industries and GRDC Grains Agronomy and Pathology Partnership investment operating from 2019 to 2022, trials evaluated oats, wheat, barley, triticale and canola varieties for their potential to produce grain following grazing. The species were evaluated at Tamworth and Glenn Innes, with an additional site for canola at Tamworth.

Based on 2020–22 pricing, gross margin analysis showed that for many of the grain/graze and hay treatment combinations, baling the crop for hay at growth stage 65 (GS65) was more profitable than taking the crop through to grain harvest. However, these seasons were wetter than average at the trial locations.

For oats, the greatest flexibility for grain recovery after grazing at GS30 at both trial sites was demonstrated by the varieties Eurabbie, Mannus and Nile.

Dual-purpose oat performance

Treatments at both locations were sown at three times, ranging from 13 March to 30 April at Tamworth and 5 March to 18 May at Glen Innes in 2020 and 2021.

Simulated grazing was applied at growth stage 30 (GS30). Shoot biomass, feed value, maturity, grain yield and quality data were analysed to identify the best-performing and most-profitable treatment combinations in 2020 and 2021. Feed values of all treatments were high, suiting most ruminant diets.

Yield performances of the five highest-yielding ungrazed and grazed oat varieties are shown in tables 1 and 2 for the two locations. Varieties Mannus, Yiddah and Eurabbie were higher in grain production after grazing at GS30 and comparable or higher in production of dry matter at GS30, suggesting that they could be considered as higher-yielding alternatives to the long-term industry standard Nile in both environments.

For grain-only production, the oat variety SF Dynasty produced some of the highest grain yields in the ungrazed treatments at both sites and was also the fastest-maturing variety. However, it did not recover well after grazing. Due to wet conditions at harvest in both seasons, oat grain quality was lower than expected.

At the Glen Innes site in 2021, varieties Nile and SF Dynasty showed the least storm damage and highest retention of grain compared to the other oat varieties in the experiment and were the only two varieties that were harvested for grain .

Table 1: Grain yield (t/ha) and sowing date (SD) of the five highest-yielding ungrazed oat treatment combinations at the Tamworth and Glen Innes sites for two seasons (varieties that produced the same yield from the same sowing date are grouped). ¹ Due to weather/bird damage in 2021, only the varieties Nile and SF Dynasty were taken to grain harvest at Glen Innes

Source: NSW DPI

For several treatment combinations, grazing at GS30 improved grain recovery compared with the ungrazed treatment, including Eurabbie oats. This is likely due to the positive effect of grazing in reducing lodging, particularly in wet or high-growth-potential seasons.

Table 2: Grain yield (t/ha) and sowing date (SD) of the five highest-yielding grazed oat treatment combinations at the Tamworth and Glen Innes sites for two seasons (varieties that produced the same yield from the same sowing date are grouped). ¹Due to weather/bird damage in 2021, only the varieties Nile and SF Dynasty were taken to grain harvest at Glen Innes

Source: NSW DPI

A critical decision point for growers is at GS65, where the crop can be grazed again or ‘locked up’ for grain recovery.

Experiment data for both seasons and sites were used for economic analysis conducted by Fiona Scott and Dr Kanchan Joshi from the NSW DPI Agricultural Economics and Biometrics unit.

Gross margins per hectare were generated for all species and treatments and should be interpreted in the context of the relative grain, hay and livestock prices used at the time of calculation, which were oats, triticale, feed wheat and feed barley $242/tonne, canola $601/t, with a 1.5 per cent price discount for each percentage point below 42 per cent oil.

On-farm wheat prices used included $277/t for Prime Hard/H1, $266/t for Australian Hard/H2, $262/t for ASW and $258/t for APW. Cereal hay was priced at $230/t and canola hay at $210/t.

Cattle (for grazing cereals) prices were sourced from the Meat & Livestock Australia Eastern States National Livestock Reporting Service historic data for 2020 and 2021. Cattle were assumed to be purchased at 300 kilograms/head liveweight at $4.29/kg. Sale prices used were $4.67/kg liveweight for 330 to 400kg/head, $4.01 for 400 to 500kg/head and $3.99 for 500 to 600kg/head.

Lambs were assumed to be used for grazing canola and a low-risk grazing operation was assumed, since the canola planting occurred relatively late in the season, limiting the time available for grazing. It was assumed that larger, high-quality lambs would be purchased and grazed for additional weight gain.

An example of the comparative gross margins for Tamworth shows that the top five most-profitable options were grazing and grain or hay options for all wheat in 2020 and all oats in 2021 (Table 3). The first times of sowing for grazing and hay and second times of sowing for both grazing and grain and grazing and hay were most profitable for both years

Table 3: Top five most-profitable gross margins per hectare for Tamworth, 2020 and 2021.

Source: NSW DPI.

For maximum grain-only production from the dual-purpose varieties in both environments, highest grain production was achieved at later sowing dates. However, this might not suit growers who need early grazing opportunities as biomass production generally declined as sowing dates got later. A balance must be struck in choice of variety and sowing date.

It is therefore recommended – where practical – to stagger or split sowing dates to spread the risk of damage from adverse weather and to increase opportunities for both grazing at GS30 and grain (or hay) recovery depending on seasonal conditions and prices.

Encouraging growers to adopt these system changes to increase grain production will require ongoing agronomic support, particularly in the higher-rainfall regions of north-eastern NSW and where livestock grazing systems currently dominate.

More information: Dr Natalie Moore, natalie.moore@dpi.nsw.gov.au