Canola was one of the four crops to be sown as part of this project. Topdressing rates and timings were based on gut feel and calculations based on soil nitrogen assessed by taking soil cores to 60cm were taken in mid-June, once the crop was established.

What did the soil nitrogen tests reveal?

The 2023 season results were interesting in that they were quite high despite the fact that the trial site was flooded in late 2022. Soil testing after the previous flooding in 2011 revealed low soil N. Soil testing in 2024 saw soil N levels at a more typical level demonstrating that soil N can be quite variable and making assumptions can lead to unnecessary fertiliser application/expense when a relatively inexpensive N soil test can provide accurate data. In fact, the soil N levels were so high (approximately 140 kg N/ha in June) that there were no dry matter or grain yield responses to added N. 

The rates for the typical or ‘gut feel’ treatments were based on the average rate of N applied over the previous 6 seasons at the IFN Trial Block.

Did timing and N rate make a difference?

There was an assumption that N applied early would create a more vegetative crop that could favour hay production in a dry year. Conversely, delaying N application would reduce excessive vegetative growth, while maintaining grain yields. Although later N application is also linked to higher grain protein/lower oil content, this has not been observed in any of the canola n trials to date.

The 2023 results showed no difference in dry matter or fodder yields sampled at late flowering from the different N timings or N rates.

However, grain yields were increased with the application of an extra 50 kg N/ha to approximately 3.5 t/ha, an increase of half a ton over the ‘nil’ treatment. Timing of the N did not matter, indicating there was sufficient N in the soil to get the plants to at least late flowering and needed a small boost late in the season.

2024, with lower starting N of approximately 90 kg N/ha in June, saw grain yields range from 205 t/ha (‘nil treatment’ to 3.2t/ha (calculated treatment of 90 kg N/ha). There was no clear winning timing strategy (both 6 leaf or early flowering) and the ‘correct’ rate was between 75 – 90 kg N/ha, and any N over that did not result in more yield. 2024 was a odd season in that flowering period was curtailed, seeming by rapid shift from warm to cold in early September.

You may have improved yields but what does that mean to the bottom line?

Obviously, in 2023 where the best grain yield was achieved with 50 kg N/ha, the return was $1192/ha or $518/Ml. The returns from canola hay worked out at about 2/3 of the grain return but its difficult to determine as canola has a poor reputation as a hay, based on some pretty poor offerings in previous droughts. So, in theory it can produce a quality feed when cut in flower but there is a hesitancy from buyers.

So, I think you would need to have a buyer ready before making the decision to cut for hay. The theoretical best gross margin from a dry year is still as hay rather than grain but finding a buyer might be the hard part. Water saved from the cereals cut for hay may come in handy to finish the canola for grain – a gross margin would soon sort that out!

Comparing this with prices from December 2018 (a drought year) when commodity prices where $340ML for water, $740/t grain and $300 t/canola hay, then the gross margin returns for grain were reduced to $571/ha or $248/Ml for grain and despite buyer resistance improved for hay at $1009/ha or $630/Ml.

2024 saw the best gross margin being the ‘calculated’ topdressing rate at approximately $1600/ha or $600/Ml

Key learnings & recommendations?

• Regardless of crop type, the key decision was to measure the amount of soil N that was present in the paddocks. Experience from flooding in February 2011 showed poor soil N at sowing and so using this experience would have meant excessive N rates applied for poorer returns. Flooding of the demonstration site occurred late in October 2022, and soil testing to determine soil N at sowing or shortly after would have alerted growers to the historically high levels of soil N and thus calculate an N budget based on actual figures.
• The calculated N budget had the highest yield and best gross margin. IFN has already adopted a smaller N requirement per tonne of grain than the dryland rule of thumb.
• The application of N early in the season had no influence on biomass or hay.
• The decision to cut a crop for hay rather than grain is not just based on economic returns. Marketability would play a large part in the decision to turn a canola crop into hay.

Wheat was one of the four crops to be sown as part of this project. Topdressing rates and timings were based on gut feel and calculations based on soil nitrogen assessed by taking soil cores to 60cm were taken in mid-June, once the crop was established.

What did the soil nitrogen tests reveal?

The 2023 season results were interesting in that they were quite high despite the fact that the trial site was flooded in late 2022. Soil testing after the previous flooding in 2011 revealed low soil N. Soil testing in 2024 saw soil N levels at a more typical level demonstrating that soil N can be quite variable and making assumptions can lead to unnecessary fertiliser application/expense when a relatively inexpensive N soil test can provide accurate data. In fact, the soil N levels were so high (approximately 150 kg N/ha in June) that there were no dry matter or grain yield responses to added N.

The rates for the typical or ‘gut feel’ treatments were based on the average rate of N applied over the previous 6 seasons at the IFN Trial Block.

Did timing and N rate make a difference?

There was an assumption that N applied early would create a more vegetative crop that could favour hay production in a dry year. Conversely, delaying N application would reduce excessive vegetative growth and using more soil water, while maintaining grain yields. Later N application is also linked to higher grain proteins which can attract a higher price.

The 2023 and 2024 results showed no difference in dry matter yields or stems/m² sampled at milky dough stage from the different N timings.

The fodder and grain yields of the 2023 trial were not influenced by fertiliser timing or rates. This was due to unexpectedly high N level at sowing. The site had been flooded during the previous growing season, and the common “rule of thumb” assumes low residual nitrogen levels in this scenario. This highlighted the risk of getting it wrong when using rules of thumb or gutfeel when determining what nutrients are available to plants from the farming system and the benefit that soil testing, particularly deep soil nitrogen, can provide in fertiliser decision making.

Timing made no difference to grain protein in 2023 where there was sufficient N in the soil to reach 10.5% and rates of up to 150 kg N/ha only saw a modest 0.6% increase irrespective of timing (GS 30 or GS32) although the treatments that saw a portion of the 150 kg N/ha applied at sowing tended to have slightly lower grain protein. In the more N responsive 2024 season, the timing trend was similar to 2023 but the higher rates on N did result in a yield increase. The boost to grain protein from the N was slightly greater at 1.1% over the ‘nil’ control. 2024 did differ from the 2023 trial by having a treatment based on soil N in June. This calculated rate (112kg N/ha topdressed) had similar yield to the ‘high’ rate (150 kg N/ha) and met H2 receival standard.

You may have improved yields but what does that mean to the bottom line?

As the highest grain yield in 2023 was achieved without additional N, the best gross margin was from the ‘nil topdressed’ treatment.

Using 2023 season prices at $1324/ha or $681/Ml assuming a grain price of $327/t for APW wheat. Every 50kg of N applied would result in a loss of $85/ha assuming urea was priced at $850/t.

Hay gave similar returns to that of grain on a per hectare basis, but better return per Ml thanks to the amount of irrigation water used in the spring being halved (grain required 2 irrigations of 0.8 Ml/ha while hay only required one irrigation).

As hay, assuming a price of $200/t and conservation costs of $75/t, hay returned a gross margin of $1388/ha or $816/Ml. 

2024 saw the grain option return about $200/ha better return than hay or roughly the same return per Ml

However, if the season was a dry season/low allocation similar to 2018, then the returns based on the 2023 yields were better as hay with a 35% better return/ha or 100% better return per Ml over grain production.

Comparing this with prices from December 2018 (a drought year) when commodity prices where $340ML for water, $375/t grain and $300t/wheaten hay, the returns for grain were $1711/ha or $658/Ml and $2304/ha or $1355/Ml for hay.

However, there are risks associated with hay production and not every grain grower has hay making equipment.

Key learnings & recommendations?

• Regardless of crop type, the key decision was to measure the amount of soil N that was present in the paddocks. Experience from flooding in February 2011 showed poor soil N at sowing and so using this experience would have meant excessive N rates applied for poorer returns. Flooding of the demonstration site occurred late in October 2022, and soil testing to determine soil N at sowing or shortly after would have alerted growers to the historically high levels of soil N and thus calculate an N budget based on actual figures. This would have seen a saving of many hundreds of dollars (in the case of wheat, a saving of $255/ha) for the cost of approximately $100 for the testing of the whole paddock.
• The application of N early in the season had no influence on biomass or shoot numbers and so did not encourage a more vegetative crop that would produce more hay than a crop targeting grain.
• Looking at the grain yields from the ‘nil’ treatments’, it suggests we may be a bit more efficient with our N budgets than the current dryland based ‘rules of thumb’ suggest.
• The decision to cut a crop for hay rather than grain is not just based on economic returns. Availability of machinery or contractors does play a role and the grower’s appetite for risk from weather damage also plays a part in the decision.

Barley was one of the four crops to be sown as part of this project. 2023 topdressing rates and timings were based on gut feel and the trial was revisited in 2024 but included a topdressing rate calculated on soil nitrogen assessed by soil test results from cores taken to 60cm in mid-June, once the crop was established.

What did the soil nitrogen tests reveal?

The 2023 season results were interesting in that they were quite high despite the fact that the trial site was flooded in late 2022. Soil testing after the previous flooding in 2011 revealed low soil N.

Soil testing in 2024 saw soil N levels at a more typical level demonstrating that soil N can be quite variable and making assumptions can lead to unnecessary fertiliser application/expense when a relatively inexpensive N soil test can provide accurate data. In fact, the soil N levels were so high in 2023 (approximately 150 kg N/ha in June) that there were no hay or grain yield responses to added N.

The rates for the typical or ‘gut feel’ treatments were based on the average rate of N applied over the previous 6 seasons at the IFN Trial Block.

Did timing and N rate make a difference?

There was an assumption that N applied early would create a more vegetative crop that could favour hay production in a dry year. Conversely, delaying N application would reduce excessive vegetative growth, while maintaining grain yields. Excessive late N application is also linked to higher grain protein which can reduce the grain quality to feed and possibly a lower price.

The 2023 and 2024 results showed no difference in dry matter yields or stems/m² sampled at milky dough stage from the different N timings.

The fodder and grain yields of the 2023 trial was not influenced by fertiliser timing or rates. This was due to unexpectedly high N level at sowing. The site had been flooded during the previous growing season, and the common “rule of thumb” assumes low residual nitrogen levels in this scenario. This highlighted the risk of getting it wrong when using rules of thumb or gutfeel when determining what nutrients are available to plants from the farming system and the benefit that soil testing, particularly deep soil nitrogen, can provide in fertiliser decision making.

Timing made no difference to grain protein in 2023 where there was sufficient N in the soil to reach 11.6% and rates of up to 150 kg N/ha only saw about a 1.0% increase irrespective of timing (tillering, GS 30 or GS32). Any additional N applied saw grain protein exceed 12% and fail malt specification, with the trend to increased protein as N rates increased. Complicating the response to N was the lodging of the plots from early stem elongation due to excessive vegetative growth encouraged by the high soil N and exacerbated by additional N.

In the more N responsive 2024 season, the response to timing was different to 2023 in that there was a yield response to later N application – GS32 was the late timing but poor rainfall over the 2024 winter didn’t really see any N response until irrigation in late August.

Yields ended up being around 9 t/ha, with the calculated rate (which was 112 kg N/ha) slightly lower than the 100kg N/ha ‘long term rate” applied at GS32. So in this case a guestimated rate did fare quite well. But I think it points to the fact that we use ‘rules of thumb’ to work out the amount of N required per tonne of grain, and these are based on dryland experience. The Flexible Farming System trials had ‘nil’ treatments that demonstrated that we may have better Nitrogen Use Efficiency than the drylanders. Therefore our calculated rate was potentially a bit too high – or about 25%.

What does that mean to the bottom line?

Grain gave better returns to that of hay in 2023 by about 20% on a per hectare basis, but hay had a 25% better return per Ml thanks to the reduced amount of irrigation water used in the spring being halved (grain required 2 irrigations of 0.8 Ml/ha while hay only required one irrigation).

As hay, assuming a price of $250/t and conservation costs of $75/t, hay returned a gross margin of $1723/ha or $957/Ml.

2024 saw the grain option return about $300/ha better return than hay or but hay had about a $200 better return per Ml

However, if the season was a dry season/low allocation similar to 2018, then the returns based on the 2023 yields were better as hay with a 10% better return/ha or 100% better return per Ml over grain production.

The 2023 results with prices from December 2018 (a drought year) when commodity prices where $340ML for water, $375/t grain and $300t/cereal hay, the returns for grain were $1711/ha or $658/Ml and $2304/ha or $1355/Ml for hay.

The 2024 results using the same scenario saw hay returns slightly better than grain on a per hectare basis but once again a 100% increase on a per Ml basis.

However, there are risks associated with hay production and not every grain grower has hay making equipment.

Key learnings & recommendations?

• Regardless of crop type, the key decision was to measure the amount of soil N that was present in the paddocks. Knowing the soil N allows a more informed, although not perfect, N strategy. This would have seen a saving of many hundreds of dollars (in the case of barley in 2023, a saving of $350/ha) for the cost of approximately $100 for the testing of the whole paddock.
• The application of N early in the season had no influence on biomass or shoot numbers and so did not encourage a more vegetative crop that would produce more hay than a crop targeting grain.
• We may be able to target our N budgets a bit more precisely if we get a better handle on our Nitrogen Use Efficiency under irrigated conditions, with possible N savings of up to 25% over current rules of thumb.
• The decision to cut a crop for hay, while potentially quite profitable in dry years, is not just based on economic returns. Availability of machinery or contractors does play a role and the grower’s appetite for risk from weather damage also plays a part in the decision.

Faba beans was one of the four crops to be sown as part of this project. The trial was sown as if it were for grain and samples taken for dry matter and quality assessments from late October onwards when the beans had begun to firm up.

Did the dry matter figures meet expectations?

Yes, we saw a range of dry matter yields in the range of 15 – 20 t/ha over the two seasons, which is considerably more than what would be expected from irrigated vetch. The dry matter reached a peak at that mid-podfill stage and then plateaued. But at this stage, dry matter was about 17% or in other words, 83% of the crop was water. If it was to be conserved as silage, then the crop would have to cut and wilted to achieve a dry matter % of about 35-40%. The crop was sampled on a regular basis to monitor the dry matter % and eventually reached 40% dry matter when the leaves had fallen off, the stems retained some green and flexibility and the beans in the pods were quite hard. This happened over a 2–3-week period.

It is an assumption that the target dry matter percentage for silaging should be 40%. Observations from the sampling showed the beans to be very firm and relatively high dry matter percentage, while the stems remained quite ‘wet’. It is also an assumption that there would be enough sugars and starch etc for the silage fermentation to occur to produce sufficient acidity for fodder preservation.

Did the faba bean samples maintain their quality?

Yes, they did

Until they became over-ripe, metabolisable energy was close to 11 MJ/kg, crude protein around 17% and digestibility above 70%. Feedtest’s rating for the samples submitted was A2

Economic results

The economics are hard to calculate as there is little market for faba bean silage at the moment. Some crops have been salvaged in previous droughts but generally for use by the grower. However, the other common irrigated legume hay is vetch which would be expected to yield 6 – 7t/ha and of similar quality. So faba beans do offer a much higher fodder yield potential.

From a quality perspective, faba bean fodder results show it to be quite a valuable feed. The dairy industry may be a potential customer where mixed rations could alleviate any palatability issues.

Key learnings & recommendations

• Faba beans could potentially be quite a productive and high-quality fodder.
• Timing the right stage for ensiling the crop is still to be addressed, with the crop rapidly changing from ‘too wet’ to ‘too dry’.
• Market acceptability is still an unknown.