• In a Morgan pea hay crop, there were no dry matter differences between any of hte P fertiliser rates in 2009.
• The most profitable application of P on average between 2003 and 2009 has been zero P/ha on a site with a strong fertiliser history and initial soil P Colwell of 41mg/kg.
• A rate of 5kg P/ha per year produced the second highest net income with the least amount of risk.

Phosphorus responses were undertaken in 2004 on a barley crop. This is a long-term trial to determine the effect of a range of fertiliser application rates of phosphorus (P) on long-term grain yields and soil phosphorus reserves. Results indicate that in paddocks with a good phosphorus history little response, in terms of grain yield and protein, will be gained from higher rates of P. However grain yields and protein were significantly higher where some P was applied compared to no P.

• There was no significant yield difference between any of the P rates in 2008
• The most profitable application rate of P on average between 2003 and 2008 has been zero on a site with a strong fertiliser history and initial soil P Colwell of 41ppm
• Maintenance rates of 5kg/ha, produced the second highest net income with the least amount of risk
• Avoid making fertiliser decisions on ‘gut feel’. Make use of tools such as soil tests and nutrient balances to determine P rates in 2009.

• Crop water use and soil analysis values were very similar between the sites comparing long term reduced tillage and stubble retention.
• Reduced tillage and stubble retention has significantly contributed to increasing organic carbon levels at these sites.
• The grain yields of wheat were greatest at the sites with higher water use efficiency for each location.

• Crop water use and soil analysis values were very similar between the sites comparing long term reduced tillage and stubble retention.
• Reduced tillage and stubble retention has significantly contributed to increasing organic carbon levels at these sites.
• The grain yields of wheat were greatest at the sites with higher water use efficiency for each location.

• Crop water use and soil analysis values were very similar between the sites comparing long term reduced tillage and stubble retention.
• Reduced tillage and stubble retention has significantly contributed to increasing organic carbon levels at these sites.
• The grain yields of wheat were greatest at the sites with higher water use efficiency for each location.

• Emergence counts early in season showed that there was no significant difference between the emergences of lupins at the three lower sowing rates.
• About 85 plants/m2 compared with 120 plants/m2 for the highest sowing rate. Interestingly enough the yields later in the season did not follow this trend.
• For further conclusions please see the attached trial report.

Using a combine harvester to manage stubble at harvest was expensive and exposed crops to greater risk of weather damage.  Harvesting tall and inter-row sowing was the cheapest form of stubble management and also gave good establishment.  Burning is cheap and effective at removing stubble, and allowed excellent establishment and greater early vigor for competition with weeds, but may not suit all paddock types.

The main messages from the workshop were:

P fertiliser inputs can be reduced in most situations and MAP will be the product of choice next year,

N fertiliser inputs will be low at sowing, but growers should top-dress crops if the season turns wet,

Work out your requirements as soon as possible and discuss these with your supplier.

The overall conclusion of this work is that even in yeras with a tight finish, screenings are unlikely to increase as a result of topdressed nitrogen.

• Malting barley needs to be sown early to optimise yield and minimise the risk of protein and screenings being too high.
• Applying fertiliser nitrogen to paddocks with high soil available nitrogen at sowing will lead to high protein and high screenings.
• Narrow row spacings wnd higher sowing rates increases yield and also minimises the risk of producing barley with high protein and screenings.

• A high application of potassium (K), 25 kg/ha and standard nitrogen (N) rates, 70 kg/ha improved wheat yield and grain quality up to 0.47 t/ha on mould boarded deep sand.
• In the presence of adequate potassium (> 40-50 mg/kg), in favourable seasons, wheat can respond to the application of N) fertiliser, resulting in high yield and protein. Where K is limited, returns from N are likely to be poor.
• The results indicate that a higher rate of K than banding 11 kg/ha K can lead to a significant increase in yield and profitability.
   

• The nitrogen application strategy that maximised grain yield was not always the same strategy to minimise nitrous oxide (N2O) emissions.
• While nitrogen applied at GS31 maximised wheat yield following field pea it produced 10 times higher emissions compared to the same application at seeding.
• The pattern and concentration of N2O emissions were similar for wheat following field pea or canola.

• In furrow remediation could be useful in managing acidity generated by fertiliser placement.
• CalSap® is a liquid product which can be used to manage acidity generated by fertiliser in the furrow.

 

The occurrence of frost and subsequent frost damage to grain crops is a complex phenomenon. The factors affecting frost damage in wheat crop include seasonal conditions (temperature, humidity, and wind), soils characteristics (topography, soil type), variety (maturity and flowering window) and agronomic management (sowing date, row spacing, and seed and fertiliser inputs). In 2012, frost had significantly damaged and reduced the grain yield for all varieties at two different sowing dates at Wickepin. On average the later sowings (8 June) yielded 1 t/ha greater than the earlier sowings (18 May). Comparatively longer season varieties such as Magenta and Calingiri flowered late, avoided some of frost damage and yielded the highest at both sowings. Preliminary results indicate varieties differed in their relative performance and resilience (i.e. ability to yield) in response to stresses of radiant frosts in both time of sowings. More comprehensive results on variety performance and frost damage will be available after measuring grain quality and sterility estimates.

Hostile subsoils can significantly constrain crop growth and water use in the Mallee and Wimmera. Although the subsoil constraints are effectively fixed, the impact they have on grain yields can vary markedly with crop type and seasonal conditions (particularly the pattern of rainfall). Electromagnetic survey (EM) techniques offer the potential to assess the distribution and extent of subsoil constraints within a paddock. Management options however are currently limited and the most financially viable strategy may be to ‘live with the problem’ where inputs such as N fertiliser are limited and crop selection restricted to more tolerant types and varieties.

Hostile subsoils can significantly constrain crop growth and water use in the Mallee and Wimmera. Although the subsoil constraints are effectively fixed, the impact they have on grain yields can vary markedly with crop type and seasonal conditions (particularly the pattern of rainfall). Electromagnetic survey (EM) techniques offer the potential to assess the distribution and extent of subsoil constraints within a paddock. Management options however are currently limited and the most financially viable strategy may be to ‘live with the problem’ where inputs such as N fertiliser are limited and crop selection restricted to more tolerant types and varieties.

From this trial:

• Grain yield increased by 7% with the addition of zinc. Effectiveness of fertiliser strategies could not be assesed with such a small increase in yield. Soil and plant tests were in the deficient range. At Z14 zinc enriched fertilisers at sowing increased leaf zinc. At Z30 a sulphate as a foliar was as effective as an EDTA chelate. 

From the whole project:

• Current guidelines are still relevant and effective for TE management.
• Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.
• No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.
• Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.
• Generally, all sources of foliar TE were equally effective.

From this trial:

• No crop response to the addition of Zinc. Soil and plant tests were in the deficient range. Zinc applied at seeding either as a granular fertiliser or as a fluid fertiliser increased leaf zinc Z14.

From the whole project:

• Current guidelines are still relevant and effective for TE management.
• Some current interpretations of soil tests are causing issues - the suggested levels to avoid deficiencies are much higher in some lab reports than is our experience from field trials. These are creating false impressions of the extent and severity of Zn and Cu deficiencies.
• No evidence of a major increase in the incidence or severity of TE deficiencies in the cropping zones.
• Fluid delivery of TEs at seeding is a valid management strategy but rates of the target TE need to be the same as used with compounded fertilisers.
• Generally, all sources of foliar TE were equally effective.

• Decision support tools such as ‘Select Your Nitrogen’ and ‘CliMate’ can help decision making with in-season nitrogen applications.
• In a decile 1 year there are limited benefits from in season nitrogen applications when yield does not increase with additional N fertiliser.
• Better economic returns result when both yield and protein are increased in higher decile years.
• It is important to understand production goal and the potential economic return of your nitrogen inputs.

• 40 kg N/ha applied upfront was the best yielding treatment for 2015, with the best protein results where the 40 Kg of N was applied as Urea.
• We found that 20 kg N/ha applied as a Zn enriched Urea product achieved a yield close to 40 kg N/ha as straight urea and we plan to test this treatment again in 2016.
• The timing and form of S application did not have any effect in 2015.

• The highest yield in 2016 at Loxton could be achieved with either 40 kg N/ha as urea or 20 kg N/ha as Zn-coat urea or Zn-enriched MAP.
• Compared to applying 20 kg N/ha as normal urea, using Zn-
coated urea (20 kg N/ha) or Zn-enriched MAP with urea (20 kg N /ha) increased yield by over 20%.
• This is the second consecutive season that Zn coated Urea at sowing (20kg N/ha) has significantly increase yield compared to normal Urea (20 kg N /ha).
• Applying foliar Zn has not increased yield at this site in 2015 or 2016.
• Nitrogen was a key driver of wheat productivity again, with 40 kg/ha N at sowing increasing yield by over 20% compared to 20 kg/ha N at sowing, but water use efficiency remained poor on this sandy soil.
• There was also no benefit in delaying N application at Ouyen, however very high rates (60-80 kg/N ha) using higher late application rates increased yield on the midslope.
• In 2016 there was a large difference in yield between the midslope (2.90 t/ha) and the nearby sand dune (0.86 t/ha) at Ouyen which could not be closed through the addition of N, S and Zn to the sand.

• The highest yield in 2016 at Loxton could be achieved with either 40 kg N/ha as urea or 20 kg N/ha as Zn-coat urea or Zn-enriched MAP.
• Compared to applying 20 kg N/ha as normal urea, using Zn-coated urea (20 kg N/ha) or Zn-enriched MAP with urea (20 kg N /ha) increased yield by more than 20%.
• Nitrogen was a key driver of wheat productivity again, with 40 kg/ha N at sowing increasing yield by over 20% compared to 20 kg/ha N at sowing, but water use efficiency remained poor on this sandy soil.
• There was also no benefit in delaying N application at Ouyen, however very high rates (60-80 kg/N ha) using higher late application rates increased yield on the midslope.
• This is the second consecutive season that Zn coated Urea at sowing (20kg N/ha) has significantly increased yield compared to normal Urea (20 kg N /ha).
• Applying foliar Zn has not increased yield at this site in 2015 or 2016.
• In 2016 there was a large difference in yield between the midslope (2.90 t/ha) and the nearby sand dune (0.86 t/ha) at Ouyen which could not be closed through the addition of N,S and Zn to the sand.

• The highest yield in 2016 at Loxton could be achieved with either 40 kg N/ha as urea or 20 kg N/ha as Zn-coat urea or Zn-enriched MAP.
• Compared to applying 20 kg N/ha as normal urea, using Zn-
coated urea (20 kg N/ha) or Zn-enriched MAP with urea (20 kg N /ha) increased yield by over 20%.
• This is the second consecutive season that Zn coated Urea at sowing (20kg N/ha) has significantly increase yield compared to normal Urea (20 kg N /ha).
• Applying foliar Zn has not increased yield at this site in 2015 or 2016.
• Nitrogen was a key driver of wheat productivity again, with 40 kg/ha N at sowing increasing yield by over 20% compared to 20 kg/ha N at sowing, but water use efficiency remained poor on this sandy soil.
• There was also no benefit in delaying N application at Ouyen, however very high rates (60-80 kg/N ha) using higher late application rates increased yield on the midslope.
• In 2016 there was a large difference in yield between the midslope (2.90 t/ha) and the nearby sand dune (0.86 t/ha) at Ouyen which could not be closed through the addition of N, S and Zn to the sand.

• The highest yield in 2016 at Loxton could be achieved with either 40 kg N/ha as urea or 20 kg N/ha as Zn-coat urea or Zn-enriched MAP.
• Compared to applying 20 kg N/ha as normal urea, using Zn-
coated urea (20 kg N/ha) or Zn-enriched MAP with urea (20 kg N /ha) increased yield by over 20%.
• This is the second consecutive season that Zn coated Urea at sowing (20kg N/ha) has significantly increase yield compared to normal Urea (20 kg N /ha).
• Applying foliar Zn has not increased yield at this site in 2015 or 2016.
• Nitrogen was a key driver of wheat productivity again, with 40 kg/ha N at sowing increasing yield by over 20% compared to 20 kg/ha N at sowing, but water use efficiency remained poor on this sandy soil.
• There was also no benefit in delaying N application at Ouyen, however very high rates (60-80 kg/N ha) using higher late application rates increased yield on the midslope.
• In 2016 there was a large difference in yield between the midslope (2.90 t/ha) and the nearby sand dune (0.86 t/ha) at Ouyen which could not be closed through the addition of N, S and Zn to the sand.

• The Yield Prophet uses the APSIM model to estimate wheat yields based on seasonal growing conditions and inputs.
• The outcomes of the Yield Prophet allow farmers to make better pre-sowing and in-crop management decisions which reduce risk and optimise returns.
• The Yield Prophet reports on crop growth during the season; availability of soil water and soil N; likely responses to N fertiliser; and calculates probabilities for yield and protein.
• The Yield Prophet is a web based service and accessible to subscribers and visitors on www.yieldprophet.com.au/yieldprophet.

• With high grain prices, small increases in productivity can significantly improve farm profitability.
• At Goolagong, NSW, wheat yields were significantly increased by the use of a balanced fertiliser regime including N, P, K, S, Mg and Zn.
• An analysis of gross margins showed that the application of secondary and trace elements would have significantly improved farm profitability.
• Zinc-efficient (Excalibur) and inefficient (Gatcher) wheat cultivars grown in calcareous subsoil with low micronutrient levels, high pH and B. Treatments were +/- basal nutrients (exc Zn) and +/-Zn.
• Gatcher produced 47% more DM tops and double the root length density of Excalibur by maturity.
• Excalibur was far more efficient in Zn uptake and 7 times more efficient than Gatcher in partitioning zinc to grain.
• Simulated dry sowing was not shown to have any detrimental effect on Zn fertiliser use efficiency.

Result: Fertiliser incubated in dry soil tended to have greater lability but diffusion was limited, although this did not have any effect on availability to subsequent wheat.

• The addition of extra nutrients and stubble management (removed, incorporated or intact) did not affect grain yield or soil carbon stocks after three years of trial work.

• Sowing at the earliest opportunity (which requires rainfall) is an important component of reducing the risk of canola production in low rainfall environments.
• The amount of N available to the crop is critical to productivity in a canola crop that has established well.
• Applying adequate doses of fertiliser N at seeding or early in the crop’s development have produced the highest grain yields but this was less important in a wet spring like 2016.
• Legumes can provide N to a subsequent canola crop, but in many cases, canola growing on legume residue will still respond to fertiliser N inputs.
• Analysis of the profit-risk context for optimal N inputs for canola produced in low rainfall environments is underway.

Increasing plant density is a tool to improve a crop’s competitiveness against weeds. This strategy did not adversely affect the yield of the varieties at the Liebe Main Trial Site in 2012. 

Nitrogen treatments did not significantly influence crop yield however, did influence grain protein. The soil nitrogen levels and season are likely to have influenced this result. Soil testing and understanding the crops requirements as the season unfolds are useful strategies to manage crop performance economically.

The environment is likely to have had the bigger influence on the performance of the varieties than plant density or nitrogen. Growing season rainfall for 2012 was lower than average and disease patches (likely Rhizoctonia) were evident at the trial. The water use efficiency at the site was 13 kg/mm given growing season rainfall (April to October) was 133mm (plus 34mm in January) and grain yields of 1.98 t/ha across whole trial.

• In wheat an application rate of 20 kg N/ha in-season was sufficient to achieve the highest yield at Hart in 2017. However, it was the 80 kg/ha treatment which maximised yield and protein to achieve the best return on nitrogen fertiliser invested.
• For barley an application of 40 kg N/ha was adequate to produce the highest yield and quality within the trial.

• Application of Mn or Mn+nitrogen increased barley yield.
• There may have been some residual value of the applied Mn.

• There was no yield response to Mn fertiliser.
• Plant and seed testing confirmed that this site had no requirement for Mn fertiliser, but they did show increased Mn levels with increasing supply.
• Claying in 2008 probably reduced the likelihood of Mn deficiency by improving soil moisture relations and therefore Mn availability.

• Summary of 2 experiments over 5 seasons esperiments.

• For wheat, sites were selected where lipins gave a large seed reponse in the previous year. Lupins produced much split seed.

• Wheat showed no response to freshly applied and previously applied Mn fertiliser

• Soil grey sands Deep phase gibson sand

• Dtpa Mn < 4.0 mg/kg soil

• However for wheat there was no grain yield response to Mn. Grain yield ranges from 3.5 -3.75 t/ha

• hence no determination on either methods of placement were possible for wheat

• Mn concentration in young leaves > 20 mg/ka & Mn concentration in grain > 30 both from nil Mn 

• Nor residual value fot wheat could be determined

 

• Applying N at GS31 increased yield but no response to manganese was measured.

• There was a dry matter response measured at anthesis to all treatments with application of manganese but due to dry season this was not translated into yield increases.

Mace was the highest yielder with the best grain quality and being a hard variety gave the best gross margin. All other varieties didn’t make their base grade of APW2 with the exception of one Magenta treatment. Adding nitrogen had a negative impact on yields and therefore gross margins with the exception of Magenta 25N, which was able to scrape into a higher bin grade. 

• In a below average rainfall year, with a very dry finish gravelly sands were still highly responsive to applied P, with 0.6 t/ha response to 60 kg/ha P over the last two years and 30 kg/ha applied this year
• Nitrogen in the absence of phosphorus did not significantly increase yield at either site.  This highlights the requirement to get your P rates tailored to your potential at seeding time, as low P rates may limit N response in a good year.
• There was strong correlation between early vigour and grain yield at both sites, again highlighting the need to establish a strong, healthy crop with sufficient early nutrition.
• Increasing plant numbers did not result in increased grain yield on poor sands.
• This trial shows that on variable light country variable rate fertiliser applications would be a useful tool to improve nutrient use efficiency on variable sands, as both sites had significantly different yield potential and nutrient requirement.

• Significant water allocation cuts have forced irrigators to optimise production with the amount of water available.
• The project has an agronomy component and a hydrology component.
• Experiments are located in Whitton, Kerang and Finley.
   

For take home messages in regards to fungicide, nitrogen and growth regular results please see the attached trial report.

• Despite three years of above average rainfall, a red calcareous sandy loam at Minnipa with soil phosphorus reserves of 27 mg/kg of Colwell P has not required any added P fertiliser for maximum cereal grain yields.

A site with high phosphorus (P) reserves needed no applied P fertiliser in 2010 to produce a 2.5 t/ha wheat yield.

• A site with high phosphorus (P) reserves needed no extra P fertiliser to maximise the yield of wheat in 2009 at MAC.

• Applying trace elements at sowing or as a foliar mid-season were equally effective in this particular year.
• Response of wheat plants to DAP with trace elements in the fertiliser compared to other methods for trace element application was variable and needs further investigation.

• MFMG and SARDI funded a wheat nutrition (Granular vs. Liquid) scoping study at three sites (Sherwood, Frances and Conmurra).
• The aim was to evaluate wheat production with either granular or liquid fertiliser inputs.
• Planning is underway to expand this study in 2019 and an application for additional funding submitted.

• Wheat grown on highly calcareous soils responded to zinc and manganese applications.
• Micronutrients were most effective when they were applied in fluid form which provided economical responses.
• There was no grain yield response when granular micronutrients were applied as a dry blend with granular NP fertiliser or as a coating on granules.

Mid-row banding nitrogen at 133 kgN.ha⁻¹ gave a similar response to topdressing the same rate at GS31. It increased yield by 1.38 t/ha and grain N by 38 kgN.ha⁻¹ to give an ANRE of 30%. Mid-row banded N created a highly-concentrated band of ammonium which appeared to mostly survive a water-logging event.

Mid-row banding N appears to be a valid application method for nitrogen in a southern Riverina irrigated context, allowing all nitrogen requirements to be placed in the soil at sowing. This is applicable where a higher yield potential is known with some confidence, and seeding equipment can handle larger amounts of fertilizer at sowing. Hence, it may also be a useful technique in higher rainfall zones, where yield potential is high and waterlogging is more common.

MRB in combination with topdressing was the most effective treatment for improving of NUE and yield

The small plot trial resulted in improved yields and NUE resulting from midrow banding, whilst the broadacre trial did not produce significant differences.

Higher wheat yields were achieved for some of the N treatments that included mid-row banding on N at South Stirlings, however, the same results were not seen at Kendenup.

At South Stirlings the combination of mid-row banding applications of N yielded significantly higher than the other treatments.

MRB of N at both seeding and tillering yielded significantly less than both combinations of mid-row banding and top dressing. 

At South Stirlings the two highest yielding treatments resulted from a combination of MRB and topdressing. These treatments also resulted in the greatest NUE. 

• Molybdenum fertiliser increased wheat grain yield in 2 of 5 years and grain weight in 3 of 5 years, indicating a deficiency of molybdenum in the soil.
• Manganese concentration in wheat grain was high but was greatly reduced following liming.

Experiment started in 1983

1986:

80 g Mo/ha in 1983 was as effective Mo topdressed in 1986.

320 g/ha of Mo gave maximum dry matter production of clover; about a 12% increase

Experiment started in 1983

1996:

80 g Mo/ha in 1983 was as less efective than Mo topdressed in 1997.

320 g/ha of Mo in 1996 gave maximum dry matter production of clover; about a 20% increase.

Residual value of Mo for subclover growth at recommended rates lasted about 13 years.

Soil pH was 4.4 with low soil extractable Al; residual value would be expected to be less as soil pH decreases & Al increases

Experiment started in 1992 reddish brown sandy loam ; soil pH (CaCl2) of 5.7.

1992:

Small (15%)  response to limesand at 1.5 t/ha & to Mo application applied as sodium molybdate.

Nitrogen concentration of medic increased from 4.2 to 5% with Mo application @ 200g/ha, 1.5 & 3 t/ha limesand.

limesand with Mo did not increase yield or N content compared with 200 g of Na molybdate alone.

Critical Mo concentratin in clover tops appeared to be 0.09 mg/kg

Combination of lime sand (1.5 t/ha) and 200 g Na molybdate recommended: increased dry matter produced by 30% above the control.

3 t/ha limesand produced the same yield without Mo.

 

Experiment started in 1992 reddish brown sandy loam ; soil pH (CaCl2) of 5.0.

1994:

Small (12%)  response to Mo application applied as sodium molybdate.

Nitrogen concentration of medic increased from 5.8 to 6.1% with Mo application.

limesand with Mo did not increase yield or N content compared with 200 g of Na molybdate alone.

Critical Mo concentratin in medic tops appeared to be 0.1 mg/kg

Combination of lime sand (1t/ha) and 150 g Na molybdate recommended

• The last application of nitrogen was applied on the 20th July. At this stage Yield Prophet indicated that to meet full potential an application of nitrogen was required. The plant available water (PAW) was 37mm at this time giving us approximately 30 days before the crop became moisture stressed. This gave us confidence to apply nitrogen knowing that the crop would continue to grow well for 30 days even without rain.
• This site was very responsive to Flexi-N. Three applications (banded, Z13, and Z30) of 40 L/ha Flexi-N in creased yield from 1.8 t/ha to 3.2 t/ha. The nitrogen use efficiency from applied Flexi-N was 27 kg grain/kg N.
• There were early responses to 85 kg/ha Agstar before N supply became limiting.
• Plant tests in July indicated that molybdenum (Mo) was deficient (as low as 68 ug/kg with 85 kg/ha Agstar Extra), so 100 g/ha sodium molybdate was applied across the trial.
• Grain protein was low (8 to 9%) due to yield dilution. Grain tests showed marginal sulphur (S) concentrations (average 0.10 mg/kg) which may have been detrimental to baking quality characteristics such as dough strength and extensibility.

• The trial at Morawa compared a canola-wheat sequence to a wheat-on-wheat sequence with either high or low input levels. Low input had lower fertiliser, lower seed density and cheaper herbicide options. We also incorporated a comparison of a very early wheat cultivar (Zippy) to a medium maturity cultivar (Wyalkatchem).
• Water use by the crop was estimated from the sum of the in-season rainfall and the change in soil water between sowing and harvest. By estimating the amount of soil evaporation as one third of in-season rainfall, we determined the amount of water used by the plant as transpiration. The ratio of crop yield to transpiration is the transpiration efficiency of the crop which has a potential of around 20-22 mm/kg/ha.
• The yield of Zippy was more stable than that of Wyalkatchem, but the earlier maturity resulted in a substantial yield penalty. Zippy yielded around 2 t/ha each year whereas Wyalkatchem responded more in better years. The yield penalty associated with the earlier maturing variety was not offset by the higher input level. Higher input actually increased the variability in annual gross margins.
• So far Wyalkatchem has a substantially greater cumulative gross margin than Zippy and there is little difference between the high and low input strategies.

• The trial at Morawa compared a canola-wheat sequence to a wheat-on-wheat sequence with either high or low input levels. Low input had lower fertiliser, lower seed density and cheaper herbicide options. We also incorporated a comparison of a very early wheat cultivar (Zippy) to a medium maturity cultivar (Wyalkatchem).
• Water use by the crop was estimated from the sum of the in-season rainfall and the change in soil water between sowing and harvest. By estimating the amount of soil evaporation as one third of in-season rainfall, we determined the amount of water used by the plant as transpiration. The ratio of crop yield to transpiration is the transpiration efficiency of the crop which has a potential of around 20-22 mm/kg/ha.
• The yield of Zippy was more stable than that of Wyalkatchem, but the earlier maturity resulted in a substantial yield penalty. Zippy yielded around 2 t/ha each year whereas Wyalkatchem responded more in better years. The yield penalty associated with the earlier maturing variety was not offset by the higher input level. Higher input actually increased the variability in annual gross margins.
• So far Wyalkatchem has a substantially greater cumulative gross margin than Zippy and there is little difference between the high and low input strategies.

• The high level of grain yield response to soil inversion is very exciting.  However, some sites have had little or no yield response while others have achieved an excellent yield response.  The key to the future success of this technique is to improve our ability to pick responsive soil types to maximise the return on investment in this technology.
• The very high level of weed control, which in some cases has been maintained for two to three years, is also very exciting.  There is no doubt that a mouldboard plough has enormous potential to decimate a weed seed bank.  However, it is imperative that the plough is set up correctly to achieve good weed seed burial.  The Smart CV site is a good example of how it can go wrong.  This site was ploughed in a rush during seeding in 2010 with a tractor that was not ideally suited to the plough (ie. not enough horsepower).  Consequently, full soil inversion did not occur and many wild radish weed seeds were left in the topsoil.  The grower knew this at the time but persisted with the trial to test the potential of the plough.  This soil is extremely non-wetting and a very big yield response was achieved. 
• The Brennan site was established in 2009 at West Moora by Dave Gartner (AgLime) using the DAFWA three furrow plough to assess the potential for lime burial with a mouldboard plough.  The site is deep yellow sand with moderate to high water repellence (water droplet penetration time 180 seconds).  Treatment with the mouldboard plough corrected the water repellence (water droplet penetration time 0 seconds).  The site was sown to wheat in 2009 and canola in 2010.  Large yield responses were measured in both years.  As yet there has been no response to lime.
• In summary, all of the growers that have purchased mouldboard ploughs have been very happy with the performance of ploughed paddocks in 2010.  Using a plough to invert the soil of a sandy, poor performing paddock every 10 to 15 years appears to be a fast, effective and economical way of renovating a paddock back to a point of high production.  Of course this machinery will have its limitations and is not a universal panacea.  However, our early studies are very encouraging.  Research into this area is ongoing and will eventually answer some of the long term questions that continue to arise.
•  
• Some of the practicalities
• Most of the growers so far have accessed machinery directly from Europe and then shipped it to Australia in sea containers.  Some growers have purchased second hand ploughs for $30,000 to $50,000. These machines have been completely dissembled and cleaned to meet quarantine standards so there are many hours of assembly work involved.  Some growers have accessed new machines for $90,000 to $130,000 for 9 to 14 furrow machines.  The cheaper machines have sheer bolt break out while the more expensive machines have hydraulic break out.  Sheer bolt machines have their limitations when it comes to rocks and stumps but have performed well nonetheless.  All ploughs imported so far are reversible and so are suited to up and back ploughing.
• A fourteen furrow machine can be set to cut 5.5 to 7 metres.  They work to a depth of 30 to 35 cm at 8 to 10 kph.  So the large machines can plough 4.5 to 7 hectares per hour at a cost of $70 to $100 / hectare (these are figures from growers).  The power requirement is 30 to 35 hp per furrow depending on soil conditions and working depth.  In good conditions a 450 hp 4WD wheel tractor can pull a 14 furrow plough but it will struggle in low soil moisture conditions.  4WD tractors often have the problem of the wide dual wheels running over the furrow which affects the depth and form of the first furrow.  Track tractors are preferred for pulling large ploughs.
• The large ploughs (12 to 14 furrow) have mainly been set up with a tool carrier that allows them to be connected to a large tractor without three point linkage.  This allows the tractor to run on level ground.  The smaller ploughs (8 to 11 furrow) are typically pulled by front wheel assist tractors in the 300 to 350 hp range with three point linkage.  In this situation, one wheel of the tractor runs in the furrow.
• There is clearly a large wind erosion risk immediately after ploughing.  Paddocks should be sown to wheat for cover immediately after ploughing (preferably the same day).  Wheat is more acid tolerant than barley and in many cases a profitable crop can be grown in the year of ploughing.  Cereals are more tolerant to sand blasting than broadleaf crops and so are the obvious choice as a cover crop.  Pay careful attention to seeding depth as it is easy to sow deep into soft soil.  Rolling of the paddock is essential after ploughing unless your hobby is towing tractors out of bogs.  Some growers are spreading seed / fertiliser and then rolling with coil packers to establish the wheat cover crop.  Relatively light rolling (eg. coil packers) is all that is necessary to firm the top 5 to 10cm of soil after ploughing.

• Wheat varieties respond differently to increasing rates of fluid phosphorus.
• The season suited Gladius and Yitpi over the very short season variety Axe.
• Mace yielded 5% better than Wyalkatchem.
• Seeding rate did not affect yield in 2009.

• Application of fluid phosphorus fertiliser on highly calcareous grey soil (P responsive) at Miltaburra significantly increased shoot dry weight and uptake of phosphorus, nitrogen, zinc and manganese and increased yield by 14% compared to granular phosphorus fertiliser application.
• Application of fluid phosphorus fertiliser on red-brown calcareous soil at Emerald Rise (non P responsive) increased shoot dry weight and uptake of phosphorus, nitrogen and manganese relative to granular phosphorus fertiliser application.
• On the red brown calcareous soils the addition of nitrogen and zinc to the fluid phosphorus fertiliser increased grain yield by 11% with no effect when added to the granular phosphorus fertiliser.
• At Cowell (red brown calcareous soil) the use of zinc with fluid phosphorus fertiliser showed a small increase in zinc concentration in tissues but no other benefits.

1. Mungbean did not respond to nitrogen fertiliser with a 1 t/ha yield and a starting soil nitrogen of ~90 kg N/ha.

2. Mungbean has limited ability to maintain its water balance in high evaporative conditions. Timely in-crop rainfall/irrigation may still not maximize yields under very hot conditions during flowering to pod fill.

3. Irrigation decreased canopy temperatures by up to 8°C. 4. Charcoal rot levels increased, with the greatest rise occurring in the irrigated trial.

1. Mungbean responded to nitrogen fertiliser with a yield of +2 t/ha when planted on a low starting soil nitrogen profile (~ 50 kg N/ha).

2. One irrigation at pod-fill increased yields by up to 850 kg/ha.

3. Applying irrigation during high temperatures reduced canopy temperature, which is believed to also improve pod filling and reduce flower abortion. 4. Mungbean can increase levels of charcoal rot.

• The waterlogging event affected all treatments, such that both the chlorophyll content index (CCCI) and normalised difference red edge (NDRE) were similar for all treatments immediately after the water-logging event.
• The topdressed treatments recovered better after the waterlogging event than the mid-row banding (MRB) treatments.
• MRB showed an acceptable yield and apparent nitrogen recovery efficiency (ANRE) in both waterlogged and non-waterlogged conditions, but similar or less than N topdressing treatments. The topdressing treatments had surprisingly high ANRE.
• The mid-row banded nitrogen declined during the season, presumably with nitrification and uptake. Some mid-row banded nitrogen was still evident 131 days after sowing.
• The majority of the mid-row banded nitrogen was present as ammonium during the season, which allowed it survive the waterlogging event

Nitrous oxide losses from nitrogen fertiliser products compared in this trial were low: 1 g N/ha/day or less. Granular urea and granular urea plus inhibitor fertiliser provided the greatest yield benefit this season. Potential benefits from different fertiliser products will be realised if seasonal conditions and timing of plant growth are matched.

• Natrakelp applied to the foliage showed no yield advantage in any of the crop types.
• At this stage this product needs further evaluation before it is widely used.

• Adveco D, DZ and MAX all recorded grain yield higher (3-5%) than MAP at 50 kg/ka.
• At three rates of MAP (50, 100 and 150 kg/ha) grain yield was higher in MAP plus Adveco Type W treatments compared to MAP without Adveco Type W.
• Plant vigour at Z31 and Z39 of Adveco D, DZ MAX was similar to MAP at 50 kg/ha.
• Adveco products had no detrimental effect on plant establishment and are safe to use on wheat.

• For all treatments grain yield or quality was not increased compared to conventional fertiliser applications of 80 kg/ha urea alone or 60 kg/ha urea plus 50 kg/ha DAP.
• Treatments selected for nitrogen and phosphorus tissue tests showed no difference in nutrient concentrations.

• At Cummins, an increase of up to 100% grain yield in wheat to 5 t/ha over the control was reached by applying 120 kg N/ha (two split applications of 60 kg/ha each at emergence and before GS31) and extra irrigation (50 mm) at GS31.
• At Lock, up to a 19% higher grain yield to 5 t/ha was achieved compared to control by adding extra irrigation (50 mm) at GS31.
• At Minnipa, an increase of up to 31% grain yield to 3 t/ha over the control was achieved by adding extra irrigation (50 mm) at GS31 and applying 120 kg N/ha in two split applications of 60 kg/ha at emergence and by GS31.
• Water use efficiency (WUE) improved with N fertilisation by GS31 at Minnipa and Cummins.
• The split application of 120 kg N by GS31 may only be a good investment in paddocks where crops with N requirements (e.g. canola) were grown in the previous season or soil N at sowing was low (less than 44 kg/ha) and with average or above average seasonal soil moisture at GS31.

• Volatilisation losses were small on Mallee sandy loam at Walpeup where 4mm of rain fell two days after fertiliser application.
• Volatilisation losses from the application of urea to Wimmera clay was as high as 26 percent with small rainfall events (< 4mm) in the 20 days after application.
• Significant nitrogen losses were experienced when ammonium sulphate and liquid UAN were applied to Wimmera clay. Both products lost 12 percent of applied.

• Grain yield was driven by biomass production rather than harvest index.
• Timing of nitrogen had relatively little impact on yield or nitrogen response.
• Nitrogen rate had little effect on total crop water use.
• Nitrogen use efficiency and water use efficiency were improved with additional water availability (irrigated treatment).

• With a soil nitrogen (N) content of 103 kg N/ha at sowing, Mace wheat yielded 3.1 t/ha with no N fertiliser applied and contained 6.6% protein.
• Optimum gross margins were recorded with 75 kg N/ha, though none of the N levels up to 100 kg N/ha reached 9% protein.
• Yield response was greatest for N application timings at sowing, GS31, or a split application between GS31 and GS39.
• A crop sensor was used to measure in season nitrogen responsiveness and was able to predict the optimal N rate.

• At Minnipa the late sown (resown due to mice damage) wheat gave a yield response to 20 units of up-front N, but not to N applied in-crop in 2010.
• At Mudamuckla there was no response to applied N above base rates on soil with adequate N content in 2010.

• Products with low cost per unit N were the most profitable in 2013.
• Very high N treatment increased quality but reduced yield.
• Some products that claim to increase N efficiency require further investigation.

 A grain yield of close to 6t/ha was achieved where a high rate of nitrogen fertiliser was combined with the application of animal manure to replicate high fertility soils.
 The manure alone increased yield by 0.75t/ha and raised the bar on our understanding of achievable yield for canola for this environment.
 Yields responses to granular urea N peaked at 150kg N/ha and similar yields were achieved between 150, 225, and 300kg/ha of applied N.

 A grain yield of close to 5t/ha was achieved where a high rate of nitrogen fertiliser combined with the application of animal manure to replicate high soil fertility.
 The manure alone increased yield by 0.77t/ha. The high rate of manure applied may not always be profitable but shows that yield is being limited by nutrition beyond just fertilisernitrogen application.
 Yield responses to applied nitrogen fertiliser plateaued at 75kg N/ha and similar yields were achieved between 75, 150, 225, and 300kg/ha of applied N (urea).

 Nitrogen fertility (from the soil and from fertiliser) is crucial for growing Hyperyielding canola:
o The highest N rate was the highest yielding treatment at 5.44 t/ha.
o The overall fertility of the paddock was strong, with a yield of 4.14 t/ha where only the base level 45 kg/ha N (130 kg/ha MAP and 150 kg/ha SOA) was applied.

 The oil penalty from extra N application may not be as pronounced in Hyperyielding environments:
o Canola oil concentration typically declines (in low-medium rainfall environments) with increased nitrogen application. This was not the case in this trial with N rates from 45 to 225 kg/ha.

Four nitrogen fertiliser products were compared for efficacy in relation to providing the crop with sufficient N to optimize production at two sites, Birchip and Marnoo. The products compared were: granular Urea, granular Calcium Ammonium Nitrate (CAN), liquid Urea Ammonium Nitrate (UAN) and liquid Urea. The products were applied three times (pre-sowing; at the five leaf stage and at the end of tillering).

• Paddock variance was measured across two paddocks through EM (electromagnetic) surveys. Based on this variance, high and low EM zones were identified.
• Two small plot trials compared nitrogen (N) response in a high and low EM zone of two paddocks sown to Trojan wheat, one in Yarrawonga (sown 22 April) and the other in Dookie (sown 12 May).
• • Both paddocks had high levels of nitrogen available in the soil (120–200kg N/ha 0–60cm) irrespective of zone.
• The largest response to nitrogen (1t/ha) was observed in the high EM zone at Dookie, where the highest levels of available soil nitrogen were recorded (200kg N/ha).
• Dry matter (DM) differences and normalised difference vegetation index (NDVI) readings at the Dookie site suggested the crop canopy was responding to applied nitrogen; this indicates the crop did not benefit from the high levels of soil nitrogen present (possibly as a result of later sowing or subsoil constraints).
• At the Yarrawonga site there were no significant indications from NDVI readings that a response to nitrogen fertiliser was likely; this was supported by high grain yields in the nil nitrogen plots (5.8t/ha and 6.4t/ha in the high and low EM zone respectively).
• At the Dookie low EM site, grain protein of 11.9% in the lowest-yielding treatment suggested there was sufficient soil nitrogen available to meet crop yield and protein requirements; this contrasts with in-crop NDVI measurements, which suggested the crop would respond to applied nitrogen.
• At Yarrawonga nitrogen application strategies based on NDVI readings meant nitrogen application was
• delayed until third node (GS33) in the high EM zone, which resulted in only limited uptake. A slightly earlier second node (GS32) application in the low EM zone resulted in an excellent response (0.39t/ha)to the NDVI-based approach.

Key findings:

• This site was only moderately responsive to nitrogen (N) application. Yield and protein generally increased in all varieties with the 20 kg N/ha and 40 kg N/ha rates. However, yield decreased with higher application rates.
• Protein and screening levels increased with N rates above 40 kg N/ha.
• KioraA produced the highest screening levels. The sowing date of 5 May at Nyngan is probably a bit late for KioraA, which would have exacerbated screenings.
• Varieties with comparatively lower biomass such as DartA, LancerA, SpitfireA and SunmateA maintained higher yield and lower screening levels even with the higher N application rates with a corresponding lower impact on harvest index also observed in these varieties.

Conclusions:

Conditions at sowing were very wet. There was no effective in-crop rainfall after August and combined with temperatures above 35⁰C in September resulted in a hard finish to the season.

This site had a high background starting N level (233 kg N/ha) which was surprising given the history of continuous cropping – 17 years of crop (Wheat 40%, canola 20%, barley 20%, pulse 20%) with additional N (above starter fertiliser application) only applied once in 1999. The lower rates of 20 and 40 kg N/ha gave modest yield increases in most varieties however rates higher than this tended to reduce yield and also caused screenings levels to increase in this trial. Protein levels increased with N application rates of 40 kgN/ha and above as seed size decreased.

Biomass and harvest index data (data not shown) showed that increasing N rate in heavier strawed varieties such as EGA_Gregory, Viking, Kiora produced more dry matter with comparatively less grain yield i.e. lower harvest index.

• A mean yield of 5.97 t/ha was achieved for teh 2009 nitrogen response trial at the Inverleigh site.
• There was no significant differences in yield across the trial.
• The variety used for this trial was Preston.
• Grain quality achieved AGP1 for all treatments with low test weights and low protein levels the contributing factors.
• For further take home messages please see attached trial report.

• Technical difficulties limited the value of data collected from this trial.
• There was no yield response to nitrogen rate, source or placement but protein increased with N rate.
• Nitrogen-use efficiency was in general poor across all treatments although banded treatments were slightly better than broadcase applications.

• Urea increased wheat grain yield significantly over the nil when banded at sowing.
• There was no significant difference between urea, UAN or MAXamFLO when applied at the same rate of nitrogen and incorporated by sowing, banded or applied at pre-sow, banded and post.

With extremely dry conditions following both sowing on 6 June and nitrogen application, there was no response to nitrogen application in this trial, despite the low level of available soil nitrogen (52kg/ha N, 0-130cm) recorded at the start of the season. • With yields in the range of 1.3-1.6t/ha, there was no response to applied nitrogen regardless of the timing or product used. • There was no evidence to indicate that, under these conditions, liquid fertiliser (Easy N - 32% w/w (16% urea, 8% nitrate and 8% ammonium) or Green Urea 14 (an agrotain urease inhibitor coated urea) were superior to straight urea (46%N).

• Later applications of nitrogen (GS30 & GS37) were the most profitable with the highest yield and quality, for malt barley in 2010.
• There was no significant differences in yield of varieties between early and later sowings.
• Crop sensors provide a good measure of nitrogen response and can improve nitrogen use efficiency.

Variable rate fertiliser application has a real and profitable place in the Mallee when combined with good paddock science. The precision technology gives the ability to examine the yield data for many effects including other possible influencing factors such as elevation, slope aspect or orientation to the sun, and probably many others. Grain yield was recorded continuously during harvest and logged against GPS position. From the resultant yield map it was possible to isolate treatment strips and EM38 zones within these strips and determine the yield for individual strips and therefore treatments, and also where these treatments intersect with the paddock zones. Trial was statistically analysed and Table 1 above shows there was no significant difference between treatments.

There was a significatn difference (P < 0.05) in the yield and protein levels between varieties but there was no difference in yield and protein due to the different fertiliser treatments within a variety.

• In a variable trial there were no significant differences in grain yield (machine harvested) due to row spacing 500mm v 750mm (20” v 30”), plant population (85,000 v 120,000 pl/ha) or N rate 300 v 450 kg N/ha).
• Overall grain yield average in the trial was 16.47 t/ha.
• Although no yield differences were recorded it was noted that narrower row spacing produced more overall harvest biomass, particularly at the lower plant population.
• Since there were no difference in grain yield associated with narrow row spacing and lower plant population, harvest index was reduced.
• Crop canopies at harvest contained more nitrogen than was applied as fertiliser indicating that at 300 kg N/ha applied as much as 235 kg N/ha was supplied from the soil.
• Increasing N fertiliser applied from 300 to 450 kg N/ha did not result in any greater N offtake in the crop at harvest, indicating that N was either left in the soil or lost.

• The average grain yield (header harvest) of the trial was 17.12t/ha with no indication that increased nitrogen rate (from the use of pre-drill urea) significantly increased yield when 207kg N/ha was subsequently applied in crop as fertigation.
• The lowest plant population 79,287 plants/ha resulted in the lowest yields with no grain yield difference between 91,864 and 103,620 plants/ha. 91,864 plants/ha was the most profitable.
• Normalised differential vegetative index (NDVI) assessments indicated that ground cover was significantly lower in the lowest plant population across all assessment timings up to V8.
• The most efficient recovery of nitrogen applied was recorded with plant populations of approximately 92,000 plants/ha with N applied by fertigation totalling 207 kg N/ha.

• The average grain yield (header harvest) of the trial was 16.33t/ha with an uneconomic trend for higher yields if N rate and seedrate was increased.
• Plants populations of 80,000, 93,333 and 102,222 gave no statistical difference in grain yield, grown in a maize-on-maize rotation position.
• There was a trend suggesting a response to nitrogen at higher plant populations, but this was not significant. Highest yields were associated with N uptake at harvest of 400 – 450kg N/ha.
• Grain maize established on grain maize stubble in 2020/21 was approximately 1 t/ha lower yielding than the trial in the same paddock in 2019/20 when grain maize was established in oaten hay stubble.
• Comparing the two seasons there was a significant reduction in yield last season when the population was reduced from approximately 92,000 to 79,287 plants/ha. There was no difference in this experiment with maize grown on maize stubbles.
• In terms of profitability using the yields generated, the highest margin was generated with approximately 80,000 plants/ha and 230kg N/ha applied as fertigation.
• The additional cost of N ($1.74kg/N and seed required for 17t/ha in this trial exceeded the value of 0.7t/ha grain maize valued at $210/ha, hence lowest N rate and seedrate were most cost effective.
• Last season with slightly higher yields it was the 92,000plants/ha with 297kg N/ha was most profitable.

• Grain yield was significantly higher in the narrower row spacing (500mm) at both high and low plant populations (nominally 85,000 v 106,000 plants/ha) (Caution different harvest methods were engaged for logistical reasons – see note below).
• Overall grain yield average in the trial was 16.53 t/ha.
• Total crop biomass (dry matter) at maturity was similar across all treatments suggesting narrower row spacing combined with lower plant population significantly improved harvest index and therefore grain yield.
• Of the three components (row spacing, plant population and N rate), N rate (either 300 or 450kg N/ha) had minimal influence on the yield and biomass results, since the lower rate of 300 kg N/ha met the N requirement of yield (already established 240N optimum N rate-see Trial 2).
• Row spacing and plant population did interact in the analysis of the trial data, making the assessment of the contribution of these factors difficult.
• Nitrogen use efficiency (NUE) was greatest with narrow rows, low population and 300N at 16.15kg N applied for each tonne of grain produced and 25.57kg N/t if 188kg N/ha soil supply was added to fertiliser applied (see Trial 2)

• Although increasing the frequency of N applications appeared to slightly increase grain yield (machine harvested) compared to all “up front” in seedbed yield differences were not statistically significant.
• As a general comment, timing of N application did not affect the grain yield, whether it be all up front or split over 4 timings up to V6.
• The nil applied N treatment yielded 9.49t/ha.
• However N content of the grain at harvest was greater where split applications involving later timings were compared to all the nitrogen applied at sowing indicating greater N fertiliser efficiency
• However, unless there is a premium for the maize protein in the grain resulting from later N timings the difference may be of little value to the grower.
• Soil N prior to sowing and watering up was 25 kg N/ha (0-60cm). The nil treatment contained a total of 147 kg N/ha at harvest, suggesting in-crop mineralisation resulted in 122 kg N/ha released to the crop.

• In all treatments where N fertiliser was applied there were no statistically significant differences in grain yield.
• The highest yield achieved was 16.82 t/ha with the total applied N of 300 kg N/ha, applied as 100 kg N/ha at sowing, then 3 subsequent topdressings of 66 kg N/ha up to tasselling, but achieved similar yields to applying 300 kg N /ha at sowing only.
• The nil applied N treatment yielded 10.61 t/ha and had a dry matter of 19.58t/ha and a N content of 176kg N/ha at harvest.
• Soil available N prior to sowing and watering up was 44 kg N/ha (0-60cm).
• The nil N applied treatment contained a total of 176 kg N/ha at harvest, suggesting in-crop mineralisation resulted in 132 kg N/ha being released from the soil during the course of the season.
• In this trial as long as at least 100 N (and 200 kg N/ha in total) was applied beginning at sowing, product or timing did not influence yield.

• The highest grain yield (machine harvested) achieved was 16.36 t/ha with the applied N rate of 240 kg N/ha in a crop producing 30.63 t/ha dry matter at 50.45% harvest index.
• N applications above 240kg N/ha were uneconomic in the trial.
• The nil control treatment yielded 10.89 t/ha in a crop producing 26t/ha dry matter at 51% harvest index.
• Available Soil N prior to sowing and watering up was 34 kg N/ha (0-60cm). The nil control N offtake at harvest was 241 kg N/ha, suggesting in-crop mineralisation resulted in 207 kg N/ha of the N taken up.
• At the highest level of N (560kg N/ha) there was no advantage to applying 80 Kg N/ha of the dose very late at tasselling.

• The highest machine harvested yield achieved was 16.42 t/ha with the applied N rate of 560 kg N/ha, however this was not statistically different to the yield where 240 kg N/ha was applied.
• Yield plateaued beyond the ‘240 kg N/ha’ treatment (16.18t/ha), mirroring the 2019/20 results which produced a similar N applied optimum.
• Where no N fertiliser was applied the yield was 9.70 t/ha with a dry matter of 21.8t/ha at harvest compared to 16.18t/ha and 35.79t/ha for the optimum N rate of 240kg N/ha.
• The N offtake at harvest revealed an average N content of approximately 188-448kg N/ha in the crop with the 240N treatment giving an offtake of 395kg N/ha with 58% of the N in the grain.
• Increasing N rate from 240kg to 560kg N/ha applied did not significantly increase dry matter present at harvest, although there is evidence of additional N content in the dry matter above 240kg N/ha.
• Soil N prior to sowing and watering up was 32 kg N/ha (0 – 60cm). One month after sowing and wetting up this figure had risen to 107kg N/ha.
• The nil N treatment contained a total N content of 188 kg N/ha at harvest, suggesting in-crop mineralisation through the course of the season resulted in 156 kg N/ha released.
• In-crop mineralisation in the 2020/21 season was lower than in 2019/20 (241kg N/ha) but still contributed a significant portion of the crop N budget.

• Header grain yields averaged 18.2t/ha with no yield benefit observed from applying pre-drill urea in the trial when N was applied post sowing as fertigation.
• In a trial with an overall dose of post sowing N of 207 kg N/ha applied via fertigation there was no significant yield increase from the earlier pre-drill N applications of between 0 – 315kg N/ha.
• The economic optimum level of nitrogen applied was 252kg N/ha (45N pre-drill + 207kg N as fertigation).
• No significant differences were recorded in total dry matter (DM) content at V6 or at harvest with an average DM content of 34.6t/ha.
• The N content at harvest revealed an average N content of 462kg N/ha with a range of approximately 415-530kg N/ha in the crop, but there were no statistical differences.
• The N offtake at harvest indicated soil mineralisation provided up to 165kg N/ha to grow the crop with lower N efficiency recorded from applied fertiliser at higher overall N rates.
• There were no significant differences in test weight (mean 81.1) or harvest index (mean 51.7%).

• Header grain yields averaged 17t/ha with no yield benefit observed from applying pre-drill urea in the trial when N was applied post sowing as fertigation (230kg N applied).
• In a trial with an overall dose of post sowing N of 230 kg N/ha applied via fertigation there was no value to the earlier pre-drill N applications of between 0 – 315kg N/ha.
• No significant differences were recorded in dry matter (DM) accumulation at V5 or NDVI at V7.
• The N offtake at harvest revealed an average N content of 420kg N/ha with a range of approximately 395-460kg N/ha in the crop.
• The N uptake at harvest indicated soil mineralisation provided up to 79kg N/ha to grow the crop with lower N efficiency recorded from applied fertiliser at higher overall N rates.
• There were no significant differences in test weight (mean 80.7kg/hL)
• Dry matter at harvest showed no differences with an average reading of 35.3t/ha and harvest index mean of 46.9%.
• Exactly two thirds of the N removed in the crop was present in the grain with an average of 280kg N/ha in the grain and 140kg N/ha in the stover.