At three field sites in WA, increased wheat yield was achieved at lower nitrogen (N) application rates when N was balanced with appropriate phosphorous (P), potassium (K) and sulphur (S) applications. Wheat yield was driven by the ratio of N to P and K rather than the absolute concentrations of the nutrients and it is possible to increase profit margins by balancing nutrient inputs.

The level of background nutrients present in the soil at sowing was a key factor in determining the responsiveness of yield to fertiliser applications and how profitable the fertiliser treatments were. Pre-season soil testing to determine the level of residual nutrients will allow growers to balance their nutrient inputs and help to maximise profits.

• The site was very responsive to nitrogen (N) fertilizer. 30kg N/ha increased yields by about 0.5 t/ha (18 kg grain/kg N).
• 12mm rain fell 3 days after the N applications in June. This would have limited volatilisation losses.
• The trial site was also quite variable and no response to the urease inhibitors was measured.
• Hectolitre weights were 75-77 kg/hl, and screenings about 3%.

• Seedling densities were high at both sites, reflecting favourable conditions during spring.
• Sowing 5-10 mm below the surface into furrows resulted in a significantly higher density than the other treatments at both Gillingarra and Eneabba.
• Surface seeding into furrows gave a significantly higher density than into no furrows at Gillingarra, although there were no statistical differences between the two treatments at Eneabba.
• Surface-sown plots with no furrows were also the most patchy.

With a soil nitrogen content of 153kg N/ha at sowing, Derrimut wheat yielded just less than 6 t/ha with no N fertiliser.

Applied nitrogen (N) significantly reduced the yield of Derrimut wheat following lentils, yield being reduced from 3.2t/ha to 2.6t/ha as applied nitrogen was increased from 0 to 100kg N/ha in 25kg N/ha increments (linear relationship).

• The optimum nitrogen rate, regardless of timing, to maximise yield was 75kg N/ha, though protein contnet was maximised at higher N rates.
• Further investigation is required to define correlations between crop reflectance (NDVI) and N uptake.

• The effect of application of gibberellic acid (ProGibb) on dry matter production and subsequent grain yield of dual purpose wheat was investigated. There were large and significant increases in DM production when Pro‐Gibb was applied.
• A high rate (40g/ha) resulted in a more rapid increase in DM but by the 4th week all ProGibb treatments had produced significantly higher DM than the nil treatment.
• Average dry matter increases were around 30%, i.e. from 1.26tDM/ha to an average of 1.64t/ha.
• In contrast seven weeks after application the nil treatment produced significantly more DM than the ProGibb treatments i.e. ProGibb treated plants appeared to suffer a payback from the extra growth. Importantly this effect was not carried through to grain harvest with no significant differences between treatments being measured.

• Rhizobia symbiotially fix close to three million tons of nitrogen a year worth $4 billion.
• The Australian Inoculants Research Group (AIRG) and its predecessors have controlled and maintained the quality of legume inoculants through collaboration with industry, universities and R&D bodies for close to 60 years. 
• A symbol of inoculant quality assessment by an independent laboratory is the dispaly of the green tick logo. 
• These are different innoculant groups specific for different legumes.
• Correct storage is important to maintain high numbers of rhizobia in the inoculants. 
• The AIRG continue to monitor the quality of legume inoculants at different points in the supply chain and works closely with teh manufactures to ensure that Australia's growers have ongoing access to efficacious products. 

CAN gave a significant yield result at both timings and over both rates of urea (Table 1). The site responded to topdressed N markedly with a yield increase of 0.81 t/ha (90 Urea) to 0.93 t/ha (132 CAN) at the first timing. The second timing showed a 0.6 t/ha (132 Urea) to 0.82 t/ha (132 CAN) yield response. Both CAN responses were significantly different to Urea. The first timing gave a higher yield response with both products. There was little site variation with both controls not significantly different.

• Trifluralin was very effective, reducing ryegrass numbers by 60 percent.
• The use of oilseeds and pulse crops provided the opportunity to effectively control resistant ryegrass using different chemistries (even within Group A - dims).
• Cutting hay is a profitable option with low risk and importantly very effective in reducing ryegrass if managed correctly.

• Crop sensors are a useful tool for measuring and mapping the growth of crops, however their limitations need to be recognised.
• Poorer crop growth and lower sensor NDVI values can indicate lower N availability within a paddock, but this should be ground truthed, rather than assumed as there are many potential constraints to crop growth that could also be the cause.
• The use of an N-rich strip in conjunction with crop sensors can provide an indication of the likely grain yield response to N.
• The N rate calculation still requires a yield prediction – a potential fit with APSIM / Yield Prophet.
• Utilising predefined paddock zones created from historical yield and/or soil data may help to refine the use of crop sensors for variable rate applications.

The objective of this GRDC / SPAA funded project is to increase the level of adoption of PA 'beyond guidance' by broadacre farmers. The project specifically aims to increase the level of adoption of variable rate (VR) by growers in the project to 30% by 2013.This goal will be achieved by demonstrating how to use PA tools to growers at a regional level and by increasing the skills of growers and industry in PA to a level where they can then use PA tools in their farming systems to achieve economic, environmental and social benefits.

• Liquid P applications must be considered a viable option in these farming areas considering these results. It should also be pointed out that this is only one set of trial data in one year for this area. These results indicate that more trial work on LMAP needs to be conducted in the future. 
• Based on previous trials from other areas, the above results indicate that soils in these areas are able to tie up P and that the use of the liquid form of P as LMAP is a viable option for broadacre cropping where this occurs. 
• Finally this trial indicates that a positive yield response can be gained from additional use of N fertilisers, as seen in treatment 5, which was a combination of urea and MAP granules. 

• High rates of seed and fertiliser could indeed be a useful tool for controlling weeds. Seed costs would be a little greater but the ability to control the weeds without using chemical - particularly in a situation where resistant weeds become a problem, could certainly make the cost acceptable.

The objective of this GRDC / SPAA funded project is to increase the level of adoption of PA 'beyond guidance' by broadacre farmers. The project specifically aims to increase the level of adoption of variable rate (VR) by growers in the project to 30% by 2013.This goal will be achieved by demonstrating how to use PA tools to growers at a regional level and by increasing the skills of growers and industry in PA to a level where they can then use PA tools in their farming systems to achieve economic, environmental and social benefits.

• This site was unresponsive to N and there was no significant effect of either seed rate or N timing upon yield.
• Crop vigour was poor through the season and this was most likely related to subsoil acidity and aluminium toxicity.
• Plant testing confirmed adequate supply of nutrients.
•  

• There is an opportunity to use locally available amendments in place of inorganic fertiliser.
• High rates of surface-applied chicken litter tend to have a better yield response than either surface-applied compost or inorganic N fertiliser.
• Stability of these organic products may provide a less risky option for managing inputs with no need for top dressed urea in the first two years.

A yield increase is apparent in figures 2 (circled) and 3 (see attached Trial report) at the ripped only treatment in the eastern plot, however this is not seen in the western plots and does not stand out in graph 1. Results presented in Graph 1 generally show only slight differences with the greatest response observed in the gypsum only treatment on the eastern plots. This soil was highly sodic at 10cm and as could be expected the gypsum would make a quicker impact on sodicity, thus allowing for improved drainage that may have improved crop production. Gypsum would take longer to impact on subsoil sodicity and may show a response after several years of data are collected

Yield stability and Adopting VRT.
In the initial phase of the project, trial paddocks were selected that had a high degree of
variability. The aim was to exploit this variability to increase whole paddock profitability.
As we learnt more about crop performance in individual paddocks, it became apparent
that some paddocks had a high degree of variability from season to season as well as
between zones (i.e. a high performing zone one season could be a low performing zone
the next). This makes using variable rate technology (VRT) to achieve target yields is
very difficult.
We have developed some rules of thumb for determining if VRT is likely to be profitable
based on the percentage of the paddock that is stable through time.
Highly suited to VRT = >70% Stable
May suite VRT = 55-70% Stable
Unlikely to suit VRT = <55% Stable
Our research shows that unstable zones within a paddock are usually impeded by soil
physical or chemical constraints such as water logging, sub soil acidity, sub soil
compaction. Water logged sites tend to be low yielding in wet seasons and high yielding
in dry years. Sites with subsoil problems tend to perform like medium zones in seasons
with a soft finish and like low zones when there is a dry end to the season.
Trial results have given economic responses (up to 500kg/ha) in the first season to deep
ripping to overcome a tight subsoil.
Most trial sites have not given economic yield responses to additional applications of
nitrogen, phosphate (and potassium on some sites). To date the most profitable treatment
has been the low fertiliser input strategy in high or low yielding seasons.
7
Water Storage Determines Yield
University of Western Australia honors student Josh Whitwell joined the project to assess
how water holding capacity of soil affects yield in that zone. Josh found that grain yield
was determined mainly by a soil’s ability to store and supply water to plants. The high
productive zones commonly had soil profiles that could store larger amounts of water and
supply it back to the crop. Of the 45 sites investigated, 40 were found to have limited
rooting depth due to critical amounts of pH, EC and soil strength. This suggests there is
scope to increase grain yield by ameliorating subsoils.
Focus for 2006 and 2007
With the project extension now approved we intend to focus on continuing research on
the main trial sites to increase replication through time. We hope with the additional two
trial years we can better understand how seasonal conditions interact with zone
management.
We also intend to compare the different paddock zoning methods used by our
collaborating partners, Gamma radiometrics, (B Whelan, Sydney University) and Crop
biomass image analysis (I Mailing, Silver Fox) with zoning from actual yield data.
Economic Analysis
Over the three trial years we have seen a large fluctuation in fertiliser cost and grain
prices.
For all economic calculations the prices have been standardized to eliminate year to year
fluctuations in grain price or fertiliser cost. This has enabled comparisons through time.
• Wheat price – A net in bank wheat price of $180/t plus or minus AWB golden
rewards quality bonification (July 2005). The $180 net in bank price reflects the 5
year average for wheat delivered Corrigin.
• Malt and Feed Barley price – A net in bank wheat price of $198/t (malt) and $153/t
(feed) plus or minus quality bonification. The net in bank price reflects the 5 year
average for barley delivered Corrigin.
• Lupin price - $190 net in Bank.
• Canola price - $355/t net in Bank plus and minus oil bonification as per grain pool
July 2005. This reflects the 5 year average net in bank canola price for Corrigin.
• Fertiliser prices – 2004 Company list prices were used for all 3 trial years.

VRT Performance

Matching fertiliser inputs to productivity zones (VRT) was rarely the most profitable strategy. Table 1 summarises the 9 successful trials undertaken in 2006 and 2007. These were above 5 average production years for the Corrigin area. It is assumed that the low, medium or high fertiliser treatments were blanketed across the whole paddock. The VRT treatment involved apply low inputs to the poor productivity zone, medium inputs to the average productivity zone and high inputs to the good productivity zone. This summary shows that in 8 of the 9 trials a blanket application of low or medium fertiliser rates was the most profitable way to fertilise the paddocks. High inputs were never the most profitable approach. The VRT approach was only most profitable in 1 of the 9 trials. The high input treatment was the least profitable strategy in 6 of the 9 trials.

Phosphate responses

Many of the paddocks where we had our trials were un responsive to phosphate. Our research has shown that many soils now have sufficient levels of phosphate that crops either don’t respond to additional applied phosphate or the responses are very small. The WA wheat belt has been in a phosphate building phase since clearing. Many farms now have sufficient phosphate levels. Fertiliser regimes could now be reduced to a maintenance regime. This would offer significant savings to growers especially given that the price of phosphate has tripled in the past two years. There would also be some significant environmental benefits to preventing over fertilising.

Best Fit for VRT

We feel that in the Corrigin area the most economic use of VRT will be for patching out potassium on responsive soil types as well as ameliorating soil with applications of lime or gypsum in the areas which have the highest requirement, rather than blanket applications on areas that do not require amelioration. VRT could also be used for tactical applications of nitrogen. Where the paddock is blanketed with N and P for and average production season. In an above average season additional nitrogen should be applied to the high productivity zones where the demand for additional nitrogen is likely to be highest.

• Remote sensing can confidently be used to map a rice crop’s panicle initiation (PI) nitrogen (N) uptake.
• A remotely sensed image of nitrogen uptake at PI can identify variability in the uptake and enable variable rate nitrogen topdressing to maximise grain yield with reduced risk.
• Remotely sensed data has been collected using field spectroradiometer (SVC HR1024), multispectral cameras including the MicaSense RedEdge, Tetracam MCA and Headwall Hyperspectral Imager, and Worldview 3 satellite data.

• Blackleg internal infection was found to be greater in retained seed compared to the original hybrid.
• Some trials showed a yield loss when retained sowing seed was used.
• The use of farmer retained hybrid seed must be questioned based on these and other trial results.

Higher apparent N recovery efficiency was recorded in the topdressed treatments than the mid-row banded treatments, particularly the one topdressed early before waterlogging (TDE). There was no real difference in the N recovery between the MRB rates (190 and 290 kg/ha).

• Condition score stock every time they come into the yards and use the “Lifetime Ewe” app to guide costeffective decisions on feeding regimes.
• Ewes pregnancy-scanned for twins and singles and managed as separate mobs, enables tighter feed management of the singles without compromising the overall lambing percentage.
• Use all the tools - Pastures from Space, condition scoring Lifetime Ewe app and stocking rate calculators - to ensure mobs are not being over or under-fed (both options can lead to costly mistakes).

• SclerotiniaCM is an app to aid growers and consultants in making economic fungicide application decisions to manage Sclerotinia in canola.
• The SclerotiniaCM app correctly identified the value of applying a fungicide spray in trials and large-scale demonstrations in commercial crops in the Geraldton port zone while suggesting spraying would not be worthwhile on the south coast.
• Apothecia observations, petal infection, disease progress and yield results from both the Geraldton and Albany port zones confirmed the SclerotiniaCM app offers an easy and useful tool for making decisions on whether or not to apply fungicide for Sclerotinia management.

When using the BlacklegCM App the information contained within the predictions is an indication of potential, not a guarantee for profit. The results from the York trial, where it was more of a case of minimising the loss received rather than focusing on making a profit, showed that regardless of the predications made by the app there was always going to be a loss received at this site due to poor seasonal conditions. The BlacklegCM App is an ideal fit to provide an indication of risk to a canola crop from blackleg, and the potential economic impact of this decision (positive or negative), as the user inputs the parameters that they are assessing prior to undertaking the decision to execute this plan.

While the analysis of using the BlacklegCM app as a predictive tool could not be completed for the 2020 trial results, the data collected from this season’s trial was able to show that the new technology that has been developed to further enhance the growers ability to minimize the impact of blackleg infection is effective. The results also showed that Pioneer 44Y27 (RMR) yielded higher when compared to the BASF 3000 (MSS) used in the same trial sequence which correlated with the Stingray (MR) having a greater yield across both trial sites than the Bonito (MS) under blackleg pressure, supporting the benefits of robust blackleg resistance ratings from broader trials.

Extension of the app needs to be clear that the figures that the app develops are based on the background research, the parameters put into the app and that there is still a range of variability to allow for within the system.

The objective of this GRDC / SPAA funded project is to increase the level of adoption of PA 'beyond guidance' by broadacre farmers. The project specifically aims to increase the level of adoption of variable rate (VR) by growers in the project to 30% by 2013.This goal will be achieved by demonstrating how to use PA tools to growers at a regional level and by increasing the skills of growers and industry in PA to a level where they can then use PA tools in their farming systems to achieve economic, environmental and social benefits.

• Protein and yield responses may have been impacted by nitrogen residues in the soil from the two previous dry seasons.
• One treatment of 130kg/ha was also tested, however, due to an error during the harvesting of the trial and there being only one replicate of the treatment, the results have not been included.

The results indicate that the land owner may see economic benefit (as per Gross Margin) from the uptake of variable rate technology in paddocks with varying soil types such as this trial paddock.

The objective of this GRDC / SPAA funded project is to increase the level of adoption of PA 'beyond guidance' by broadacre farmers. The project specifically aims to increase the level of adoption of variable rate (VR) by growers in the project to 30% by 2013.This goal will be achieved by demonstrating how to use PA tools to growers at a regional level and by increasing the skills of growers and industry in PA to a level where they can then use PA tools in their farming systems to achieve economic, environmental and social benefits. Fertiliser rates were selected after discussing with farmer that the lower yielding zones would never produce yields comparable to medium and high yielding zones, due to the low fertility and poor water and nutrient holding capacity of the soil. The farmer believed that that fertiliser was being wasted on the sand zones of his farm, and wanted to see if cutting fertiliser rates would be detrimental to yield in this zone.

• Centre pivot irrigation plots were surveyed using gamma radiometric and electromagnetic sensors.
• Soil moisture sensors with 3G logging devices were installed in contrasting soil types according to interpretation of the gamma radiometric data.
• Replicated yield and quality estimates were conducted on each soil type
• Yields and tuber classes varied significantly between soil types
• Experiments to determine optimal irrigation and fertiliser regimes for contrasting soil types will be conducted in 2017.

In 2010, at Wass brothers’ property in Nyngan, a very wet season caused the normally poor performing areas to perform just as well as the good areas in this paddock regardless of additional nitrogen application. In other paddocks across the farm, there were significant yield differences across each paddock. However, in the previous years Wass’s have always wanted to apply N and have had mixed results possibly because of soil and water variability. Most seasons they have areas that burnout and areas which could use a higher application of N and give a better yield. In 2011, Hayden intended to try to understand what was driving these differences, and yield maps are a way of spatially determining different zones. Therefore, this trial was set up.

The objective of this GRDC / SPAA funded project is to increase the level of adoption of PA 'beyond guidance' by broadacre farmers. The project specifically aims to increase the level of adoption of variable rate (VR) by growers in the project to 30% by 2013.This goal will be achieved by demonstrating how to use PA tools to growers at a regional level and by increasing the skills of growers and industry in PA to a level where they can then use PA tools in their farming systems to achieve economic, environmental and social benefits.

Because there was no effect of fertiliser on the yield it meant any potential benefit from VR was greatly reduced. This can likely be put down to the high levels of soil N recorded at the start of 2011. The trial does suggest that this paddock was over fertilised as there was no significant loss of yield from a 40kg/ha reduction in urea in either trial.

There was no response shown to varying nitrogen rates across the 4 yield zones on this paddock. This could be due to the adequate levels of nitrogen present before seeding as show in the 0-10 and 10-60cm soil test results and also reinforced with the NDVI esults, this would stem from good fertiliser history and rotation from the Harkness’s.This could give confidence that rates could be reduced on the lower yielding areas without risk of impacting on yield and consequently increasing gross margins across the paddock by saving wasted inputs on poorer performing soil types and leaving rates higher on better performing areas to maximise returns when seasons are more favourable.

The trial has indicated that the application of the high rate UAN (140L/ha) over the entire paddock still proved to be a more profitable than applying the low rate over the entire paddock, however the overall gross margin benefits are not as visible due to the low yielding sand zone only occupying 9ha (13%) of the paddock. However these results confirm that the adoption of PA is an economically sound decision, indicating that the grower could make a saving of $48/ha if that extra nitrogen was not applied to the low yielding area via the use of variable rate fertiliser application. The trial results have solidly indicated that the overall gross margin would be profitably affected not having to spend the extra $62/ha on fertiliser. The gain of $53/ha in the high yield zone with high rate N (140L) is a substantial increase in profit over the low rate (60L) showing there is benefits to adding N in these zones.

Applying nitrogen on the sand soil zones has consistently delivered sound economic returns. The highest ROI achieved in the sand west zone ($123.20) and sand east zone ($37.85) was in the 115 and 130kg urea/ha treatments respectively. Applying nitrogen in the clay zone however failed to deliver an economic eturn and this has been realised in this paddock before. This trial highlighted that variable rate nitrogen is highly applicable to paddocks with high degrees of spatial variability in order to maximise yield and/or return on investment in individual paddock zones.

• Each soil zone was nitrogen responsive at varying levels.
• Low EM zones (sands and sand-loams) were very responsive - 41-61% increase in yield achieved by applying the top rate of urea.
• High EM zones (clay-loams) were moderately responsive - 10-22% increase in yield achieved.
• Applying high rates of nitrogen to high EM (clay-loam) zones proved to be un-economical.

The NDVI map has a strong correlation to the final yield, which indicates that the variable rate nitrogen did not achieve the goal of levelling out crop yield. This may be due to the dry finish to the season. This result does however confirm the concept of using in-season satellite imagery (typically late July, early August) o manage final yield through a variable rate intervention.

• In 2011 optimised variable rate N applications increased gross margins by $11- $22/ha in two barley crops.
• In 2012 variable rate N applications increased gross margins by $13-$20/ha in three wheat crops, based on yield response and fertiliser savings.
• Increases in grain protein of 0.3 – 0.5% have been observed.

The objective of this GRDC / SPAA funded project is to increase the level of adoption of PA 'beyond guidance' by broadacre farmers. The project specifically aims to increase the level of adoption of variable rate (VR) by growers in the project to 30% by 2013.This goal will be achieved by demonstrating how to use PA tools to growers at a regional level and by increasing the skills of growers and industry in PA to a level where they can then use PA tools in their farming systems to achieve economic, environmental and social benefits.

The objective of this GRDC / SPAA funded project is to increase the level of adoption of PA 'beyond guidance' by broadacre farmers. The project specifically aims to increase the level of adoption of variable rate (VR) by growers in the project to 30% by 2013.This goal will be achieved by demonstrating how to use PA tools to growers at a regional level and by increasing the skills of growers and industry in PA to a level where they can then use PA tools in their farming systems to achieve economic, environmental and social benefits.

The objective of this GRDC / SPAA funded project is to increase the level of adoption of PA 'beyond guidance' by broadacre farmers. The project specifically aims to increase the level of adoption of variable rate (VR) by growers in the project to 30% by 2013.This goal will be achieved by demonstrating how to use PA tools to growers at a regional level and by increasing the skills of growers and industry in PA to a level where they can then use PA tools in their farming systems to achieve economic, environmental and social benefits.

This year there was no big benefit from variable rate fertilizer in relation to yield. This is not unexpected given the dry season.

This trial gives some confidence that cutting fertilizer in particular P back on the low zone did not impact yield and had the best gross margin, therefore is a good strategy to reduce costs on the lower performing parts of the paddocks. This is consistent with current DAFWA and GRDC research findings that less phosphorus can be applied on soils with good P history without penalizing yield. Similarly it demonstrated the potential to reduce rates on the higher production zones depending on the season as tissue tests indicated adequate nitrogen just prior to the late N application. It is likely there was also more nitrogen available as a result of ripping increasing nitrogen mineralization and plant root access to water and nutrients. Reducing N applied after ripping is a recommended strategy to reduce the risk of the producing high biomass and the crop haying off early with a dry finish.

The estimated yield potential of the zones was not reached with the high zone about 1.5 t/ha below potential. This is consistent with farm observations that found there was a penalty of about 1 t/ha for crops sown later than 7 days from the 22nd May crops in this dry season.

High resolution six meter imagery was found to be very useful to identify management issues and map non-wetting soils, particularly the early July image which highlighted emergence issues. The non-wetting areas can be mapped and treated by ploughing those areas paddock not the whole reducing the cost of treatment. Ground-truthing showed the 6m resolution was high enough to identify problems with the bar such as running out of fertilizer. These are management issues that can be adjusted to improve efficiency and production to improve yield. 

In the case study paddock the imagery has highlighted issues that were not evident from the yield maps such as residual compaction from old corners and where the ripper and spader lifted over a water pipe (the red line in the top north east corner). This paddock has been deep ripped twice but old compaction is still visible suggesting it is beyond the current ripping depth of 400mm. The late season imagery was too late to see any big differences in biomass. An optimal time to capture imagery appears to be mid-July.

Applying low fertilizer to the low production zone is both a good economic strategy to improve profitability and prevents over fertilizing that increases the risk of nutrient leaching in these pale sands that have limited capacity to store nutrients.

On upper Eyre Peninsula few people use EM38 mapping to support the use of VRT. Currently yield maps and paddock knowledge are the most commonly used methods for determining production zones within paddocks. The demonstrations show that increasing fertiliser rates did not have an effect on yields but yields did follow EM38 mapped soil zones.

Birchip: The site was located in a paddock with moderate subsoil limitations (40 to 70cm layer had chloride reading of 1800ppm, and an EC of 0.6dS/m). The site had a previous legume history and was high in soil available N (prior to sowing the soil contained 230 kg available N/ha to 1m depth).

Kooloonong: The site was located on a Mallee land system, on a flat to sloping rise with a sandy loam soil to a depth of 40cm and at greater depth a sandy clay loam to at least 130cm. The soil has no subsoil limitations but because it is light and sandy, leaching of nutrients can be a problem. 2010 had a growing season rainfall of 329mm (decile 10).

• Further analysis using yield monitor data will allow for a comparison of fertiliser rates on the different productivity zones in the paddock which should enable us to determine the benefit from applying lower fertiliser rates to the poorer productivity areas.
• Overall the lower, more conservative, upfront fertiliser applications were the best strategy and there is still an opportunity to add more nitrogen later, depending on the season.

• At Warmur and Kalkee, Bannister was the highest yielding milling oat and Brusher the highest yielding hay oat variety in 2016 – an excellent season.
• Application of fungicides to oats did not create hay or yield benefits in the Wimmera in 2016.
• Choice of oat variety and management should be made according to the intended end-use traits – versatility if conditions change, disease resistance, ability to control problem weeds and likelihood of making premium markets.

• At Warmur and Kalkee, Bannister was the highest yielding milling oat and Brusher the highest yielding hay oat variety in 2016 – an excellent season.
• Application of fungicides to oats did not create hay or yield benefits in the Wimmera in 2016.
• Choice of oat variety and management should be made according to the intended end-use traits – versatility if conditions change, disease resistance, ability to control problem weeds and likelihood of making premium markets.

• Vetch is a versatile crop that can be used for grain, pasture, hay/silage or green manure.
• Common vetches can be successfully grown in lower to mid rainfall areas of southern Australia where no other legume crops perform consistently well.
• It offers disease and weed breaks in rotation and also returns significant amounts of nitrogen to the soil.
• New vetch species are showing potential in very low rainfall areas, with trials to be conducted on Eyre Peninsula in 2012.

When vetch is establised in March and is terminated 'early' (three to four months later, in June, July), soil water will be conserved for the subsequent wheat crop; the risk of haying off due to high nitrogen will be lower than if the vetch were terminated 'later' (August, September),

Vetch biomass production of approximately 2t/ha is unlikely to cause a subsequent wheat crop to hay off given dry seasonal conditions. 

Residual nitrogen from vetch brown manure can carry over for two years and influence cereal crop growth, but the conservation of soil water is more critical in seasons of Decile 2 or lower. 

When vetch is establised in March and is terminated 'early' (three to four months later, in June, July), soil water will be conserved for the subsequent wheat crop; the risk of haying off due to high nitrogen will be lower than if the vetch were terminated 'later' (August, September),

Vetch biomass production of approximately 2t/ha is unlikely to cause a subsequent wheat crop to hay off given dry seasonal conditions. 

Residual nitrogen from vetch brown manure can carry over for two years and influence cereal crop growth, but the conservation of soil water is more critical in seasons of Decile 2 or lower. 

When vetch is establised in March and is terminated 'early' (three to four months later, in June, July), soil water will be conserved for the subsequent wheat crop; the risk of haying off due to high nitrogen will be lower than if the vetch were terminated 'later' (August, September),

Vetch biomass production of approximately 2t/ha is unlikely to cause a subsequent wheat crop to hay off given dry seasonal conditions. 

Residual nitrogen from vetch brown manure can carry over for two years and influence cereal crop growth, but the conservation of soil water is more critical in seasons of Decile 2 or lower. 

Nitrogen (N) fixation by vetch was closely related to dry matter (DM) production (26kg N fixed per tonne DM accumulated). The later the termination, the higher the calculated inputs of fixed N. Both soil water reserves and mineral N were highest at the end of the 2012 growing season following the earliest (June and July) termination timings. To establish the best time to terminate a vetch crop, weigh up the benefits being delivered by vetch (biomass accumulation and N fixation), the need to conserve moisture and time required for N to mineralise for the next crop.

Inoculant and MAP fertiliser improved biomass yield and plant height of vetch during early vegetative stage at Kimba, Coomandook and Mundulla. This highlights the importance of adequate fertiliser and inoculant for early plant growth.

A negative grain yield and harvest index response to inoculant and MAP fertiliser was observed at Kimba under drought conditions.

There were no production responses in vetch to sulphur application.261 Very few positive responses or more often negative responses were observed in response to gibberellic acid. Further work needs to be done in this area to determine the best use for gibberellic acid in pulse production.

• In a year where waterlogging caused yield penalties all treatments resulted in a yield increase compared to the control.
• The raised beds increased yield by almost 200% followed by gravel moles, gravel slots and conventional moles.
• On flat waterlogged land, raised beds provided the best yield result but they did have some management issues.
• Gravel slots and gravel moles also worked extremely well but the slots were too expensive to install to consider for broadacre use. No commercial scale gravel mole is available at present.
• Conventional moles are prone to collapse with Kangaroo Island’s sodic clays.

• In a year where waterlogging caused severe yield penalties, all treatments resulted in a yield increase compared to the control.
• On flat waterlogged land, raised beds provided the best yield result but they do have some
• management issues .
• The delved treatment drained a considerable amount of water, yielded equal to the other treatments (but less than the raised beds) and was more cost effective to install with fewer management issues.
• Gravel slots and gravel moles also worked extremely well but the slots were too expensive to install to consider for broadacre use. No commercial scale gravel mole is available at present.
• Conventional moles are prone to collapse with Kangaroo Island’s sodic clays.

The objective of this GRDC / SPAA funded project is to increase the level of adoption of PA 'beyond guidance' by broadacre farmers. The project specifically aims to increase the level of adoption of variable rate (VR) by growers in the project to 30% by 2013.This goal will be achieved by demonstrating how to use PA tools to growers at a regional level and by increasing the skills of growers and industry in PA to a level where they can then use PA tools in their farming systems to achieve economic, environmental and social benefits.

The ‘water saving’ water crystals product did not significantly increase wheat yields and had no effect on grain quality.

The water use efficiency concept as developed by Reg Smith and and Jeff Schultz in SA provides us with a technique for assessing the performance of a crop in terms of the quality of the grain produced per millimitre of rainfall which falls over the growing season.

• A mixture of Moddus and Cycocel at GS 24 will reduce wheat plant height more reliably compared to the other treatments applied on their own.
• Plants sown into situations of higher fertility will produce taller plants that may respond better to the use of PGRs to control plant height and biomass which may improve WUE.
• For season long plant growth regulation a follow up PGR may well be required later in the season to stop plant 'bounce back'.

• The farming systems containing a perennial pasture phase contained 140-180 mm less soil water in the top 300 cm than the continuous cropping system.
• Soil under the two lucerne-wheat cropping rotations and the perennial pasture system were considerably drier below 90 cm, presumably due to water extraction by lucerne in previous years.
• At sowing, June 2004 and June 2005, the continuous cropping system contained 60 and 30 mm respectively more plant available water in the top 1 m than the lucerne-wheat cropping rotations. This resulted in 50% and 35% higher yields in 2004 and 2005 repectively.
• Rooting depth in 2004-5 appeared limited to the top 70-90 cm for wheat, 50-70 cm for peas and 210 cm for perennial pasture.
• Modelling indicates potential drainage of 19 mm annually under annual crops, thus a 2-3 year lucerne phase is capable of providing 7-9 years of buffering at average rainfall

• Site received only ‘mild’ waterlogging.
• Slow release N not given a fair trial.
• Higher N rates increase grain protein.
• No statistically significant effect of N on yield in 2012.

Engineering solutions:

• On flat waterlogged land, raised beds provided the best yield result but they do have some management issues.
• Gravel slots and moles also worked well but the slots are expensive for broad acre use.
• Conventional moles are prone to collapse with Kangaroo Island’s sodic clays.
• The nature of many of our clays (sodic and poor draining) results in poor water movement from the soil into a slotted agricultural pipe.

Agronomic solutions:

• The adverse effects of waterlogging are primarily due to anoxic conditions in the soil, rather than element toxicities or deficiencies, except perhaps for aluminium.
• Liming acidic soils will reduce al toxicity.
• In waterlogged soils the application of poultry manure doesn’t appear to improve yields. But the application of lime may increase yield.
• Waterlogging may cause nitrogen (N) deficiency but high rates of N will not turn a waterlogged crop into a good crop.
• There may be some potential for varietal difference to waterlogging in wheat.
• Broad beans: improve nodulation through a combination of liming and application of molybdenum. Liming will also reduce inherent nutritional problems of low soil pH. Early tissue testing and nutrient correction with foliar applications help overcome some soil ph deficiencies

With the aid of a 'web browser' such as Netscape, a number of weather charts and diagrams can be viewed. Of use to you will be daily rain and river height bulletins, climate data for most provincial towns in Australia, weekly rainfall analysis, the seasonal outlook and drought statement.

• Concentrating the header trash into rows prevents spreading of weed seeds across the paddock. Additionally, it allows for site specific weed management and weed seed destruction through strategic burning.
• A low cutting height (10cm) can allow greater than 95% weed seed capture and placement
  into rows. However this harvest height can impact harvest cost, speed and efficiency.

Herbicide use is becoming increasingly complicated with restrictions on the use of more and more products and a tight water supply. The following articles outline how to cope with these limitations and provide some good information for spraying this season.

This study has shown that substantial savings can be made with the use of this technology. It essntially allows the farmer to have a zero tolerance on summer weeds, without having to apply economical thresholds. The study also identified that the savings will not always result. If there is consistently, 60-70% ground cover, the economical returns may not be as great. This is due to the way the technology is designed. Often in relatively high densities, two sensors would come on to spray one weed, hence twice the amount of water. This is most likely the cause of more water being used in the areas with the High density. Overall, the Weed Seeker technology has the potential to reduce chemical costs and increase the efficiency of spray applications.

• Optical Spray Technology (OST) systems are used for broad spectrum weed control for summer weed and fallow weed control. This type of sprayer is widely accepted in broad-acre cropping situations.
• In-Crop weed detection is the sensing and identification of non-crop plants within the growing crop.
• This technology is not as advanced, nor as widely used as the optical sprayer technology.

• Significant reductions in water and chemical use can be achieved when weed sensing technology (WeedSeeker) is used, compared with blanket applications.
• Erect plants compared with prostrate plants require less spray.

• In the past four (dry) years on this demonstration farm the fallow/wheat/oats/lucerne (Phase farming) and wheat/fallow rotations have proved the most financially rewarding, probably due to the moisture storing benefits of fallow.
• Urea seems both less risky and more reliable than the pulse or ley in increasing wheat yield.
• The extreme dryness has caused problems with weed control (chemicals not effective) and with growth of pulse crops and subclover leys.

• Sowing date combined with appropriate variety selection and adequate nitrogen supply was key to increasing grain yields.
• Nitrogen fertiliser decision needs to consider the maximum attainable yield and be adjusted for the seasonal conditions and initial available soil nitrogen.

There are still many answers required before we can be confident on how to manage this important and expensive input to our farming systems.

• There are still many answers required before we can be confident on how to manage this important and expensive input to our farming systems.
• There is little chance that we can work out a profitable N management system if we do not know what happens to applied nitrogen in our cropping soils.

• Wheat yields were relatively good at all three sites considering the season.
• There were yield responses from the N topdressed fertiliser at the N response sites, Birchip and Charlton.

• The 1999 season was fairly average with a dry spring reducing potential yields.
• Nitrogen responses were marginal due to already high levels of nitrogen in the soil.
• Topdressing nitrogen on wheat increased yields at all sites to some extent.

• If you are a productive farmer, you will be acidifying your soils.
• Use the tools – they are easy to use and provide valuable information on what is driving acidity and what it is costing you and your property.
• Liming will save you money – it’s cheaper to lime than wear the cost of lost production . 
   

May 4th sown Mackellar wheat produced yields in the range of 4.74 – 5.99 t/ha following canola stubble. With high soil nitrogen reserves (176 kg/ha N, 0‐90cm) recorded 2 days pre sowing, there was a small but significant response to applied nitrogen (0.43 t/ha at 50kg/ha N & 0.58 t/ha at 100kg/ha N). There was a significant advantage to nitrogen timed during stem elongation (GS30‐39) over nitrogen applied in the seedbed. This advantage was evident in both single and split applications between which there was
no difference.

• Our standard package of 100 kg 18:20/ha at seeding under the seed row (to avoid fertiliser toxicity), Jockey-treated seed, endosulfan and simazine pre-seeding, a follow up spray of atrazine and a grass herbicide mid-season, and two top-ups of nitrogen during the season (50 kg N/ha as broadcast urea each time) gave us a clean, high yielding and good quality crop with no pests or diseases.
• There was no evidence that extra management options provided any further benefits to canola performance (ie a fungicide spray, B fertiliser or use of a growth regulant) under the conditions of last year’s trial.
• However, it would appear that we may have been a bit generous with our N and P inputs in the standard package because we could halve the mid-season N rate and not suffer any yield or quality loss. Additionally, leaving out P altogether had little impact so a rate lower than 20 kg P/ha may have been the best compromise last year.
• There seems little reason to change from a management strategy of plenty of N at seeding (providing you can avoid seedling toxicity by separating the N and the seed) followed up by an early season top-up. Delayed aapplications of N produced yields or quality no better than our standard.

• In high rainfall areas, the inclusion of an insecticide to control aphids, and therefore reducing the incidence of Barley Yellow Dwarf Virus (BYDV) should becoming common practice.
• Yield responses continue to be seen by controlling BYDC (particularly in susceptible varieties).
• In  2011, the control of BYDV also appeared to  improve the response to later applied nitrogen. 

• In high rainfall areas, the inclusion of an insecticide to control aphids, and therefore reducing the incidence of Barley Yellow Dwarf Virus (BYDV) should becoming common practice.
• Yield responses continue to be seen by controlling BYDC (particularly in susceptible varieties).
• In  2011, the control of BYDV also appeared to  improve the response to later applied nitrogen. 

• In 2010 we saw little effect of varying nitrogen rates on grain yield at Conmurra or Frances.
• Barley Yellow Dwarf Virus decreased grain yield by about 1 t/ha at both sites in 2010.
• Highest grain yield was achieved by the earlier sowing dates but very good disease control was required to achieve this.

• In 2010 we saw little effect of varying nitrogen rates on grain yield at Conmurra or Frances .
• Barley Yellow Dwarf Virus decreased grain yield by about 1 t/ha at both sites in 2010.
• Highest grain yield was achieved by the earlier sowing dates but very good disease control was required to achieve this.

• In high rainfall areas, the inclusion of an insecticide to control aphids, and therefore reducing the incidence of Barley Yellow Dwarf Virus (BYDV) should becoming common practice.
• Yield responses continue to be seen by controlling BYDC (particularly in susceptible varieties).
• In 2011, the control of BYDV also appeared to improve the response to later applied nitrogen.

• In 2010 we saw little effect of varying nitrogen rates on grain yield at Conmurra and Frances
• Barley Yellow Dwarf Virus decreased grain yield by about 1t/ha at both sites in 2010.
• Highest grain yield was achieved by the earlier sowing dates but very good disease control was required to achieve this. 

• The first sowing date produced the highest grain yields but there was a significant interaction between varieties and sowing date at each site.
• Nitrogen application rate had large effects at both sites while application time had small effects on yield and quality.
• Due to the heat wave in early November, longer season wheat varieties produced lower grain yields than earlier maturing varieties
• Control of BYDV had less effect on grain yield than in previous years.

• Across all sites, barley was more productive than wheat on both wheat and canola stubble. However in the binnu trial wheat yields were significantly higher than barley at all nitrogen treatments except the control.  
• Nitrogen is an important component of agronomy of wheat and barley in both canola and wheat rotations. Yields did respond to nitrogen. 

• In 2010 we saw little effect of varying nitrogen rates on grain yield at Conmurra or Frances.
• Barley Yellow Dwarf Virus decreased grain yield by about 1 t/ha at both sites in 2010.
• Highest grain yield was achieved by the earlier sowing dates but very good disease control was required to achieve this.

This is the first experiment to evaluate the effect of canopy architecture on wheat yield in Australia. The results show that leaf erectness appears to be an important trait for wheat in Western Australia. Erect leaves allow greater light penetration into the lower canopy.  As a result a larger leaf area and longer duration of greenness is maintained in the canopy over time (Fig. 2), both of which could increase photosynthesis and improve yield (Fig. 3). More data across a wide range of environments are needed to prove the hypothesis, and test other effects on weed competition and disease incidence. We will continue to evaluate this hypothesis with WMG in 2017, and look to broaden our evaluation with future projects beyond that.

• Despite high levels of available soil nitrogen at the start of the season (113 kg/ha N, 0 – 100 cm), there was a significant yield response to applied nitrogen. There was no yield advantage of 100kg/ha N over 50kg/ha N.
• At 50kg/ha N, there was a significant yield advantage (0.47t/ha) from application at GS33 (third node) compared to application pre-sowing.
• At 100kg/ha N, there was a significant yield advantage (0.55t/ha) from application at GS30 above seedbed application. Differences at 50kg/ha were not significant.

• With very low levels of available soil nitrogen and rooting limitations due to salinity at 70cm, there was a significant response to applied nitrogen over the zero N control, but was statistically significant only in treatments that received nitrogen in the seedbed.
• Where nitrogen was applied in-crop at GS31 (14 August) and GS39 (14 September), there was no significant yield response above the control (a result attributed to limited uptake 3.25mm of rain in August, 8.5mm in September).
• While grain protein content increased after seedbed nitrogen applications, there was no protein response to in-crop applications, confirming a lack of nitrogen uptake as a result of limited follow up rainfall.

• In this water-limited scenario, with 70 kg/ha N available in the soil at the start of the season, in-crop nitrogen application served to significantly reduce yield relative to the zero N control.
• Yield depression was strongly significant (p=0.001) when nitrogen was applied at GS30 (start of stem elongation) but was less evident when applied at GS37 (flag leaf first visible).
• Unusually, the yield reduction from GS30 nitrogen timing was associated with higher grain protein than the later flag leaf first visible (GS37) timing. This result looks likely to have been influenced by protein concentration effect accompanying the stronger yield reduction at GS30.

• Grain yields increased with the addition of nitrogen, producing a maximum of 4.64 t/ha, with 75 kg N/ha.
• Nitrogen application timing produced no significant differences to grain yield.
• Crop sensors used at early stem elongation, were able to accurately measure crop nitrogen uptake and tiller number.

• Nitrogen application timing produced no significant differences to grain yield.
• Grain yield was reduced by 12% with the presence of ryegrass.
• Crop sensors were able to accurately measure crop dry matter.

At yield levels just under 1t/ha there was no yield response to applied nitrogen in this trial at either plant population.

If measured purely in terms of yield, nitrogen (N) application was not cost effective in this trial, with 50kg/ha N producing an average yield increase of approximately 0.2t/ha.

On a site with high N at sowing, yields of 2.0-205t/ha were achieved and there was no apparent benefit from N applications of 30 and 60kg N/ha, thus all applied nitrogen treatments lost money relative to the zero nitrogen plots.

Results on a Wimmera clay illustrate that nitrogen application gave a yield increase of 0.82t/ha at 50kg/ha N and 1.13t/ha at 100kg/ha N over the zero N yields of 2.86t/ha.

The slower development of MacKellar compared to Kellalac was associated with a higher tiller count in spring. However this did not translate to higher ear numbers, since with Kellalac 75% of tillers produced an ear, compared to 65% with
MacKellar (in Hamilton the opposite occurred).g/ha Sulphur.