Phosphorus was applied as Triple Super drilled with seed. The result was lower plant densities as phosphorus rates increased.

Six varieties of canola were tested to compare their responsiveness to urea. The varieties selected had different growth patterns, and the slow growing varieties such as the TT types showed a similar response in growth to the other more vigorous types. In this experiment, urea did not increase yield of any of the varieties tested, but oil contents fell for five of the six varieties with added urea, with ATR Hyden the exception. Given the poor yield response, little can be directly interpreted from these results, although it is reasonable to conclude that higher urea rates are less profitable with lower yielding types or on sites with low yield potential.

The application of compost at 2 t/ha did not result in higher returns and the response under compost plus fertiliser treatments could be attributed to the application of fertiliser. Spading did not return any further gains in terms of yield or quality at this site in 2013. The high cost of spading and compost in the first year, have negatively influenced profit outcomes. Depending on future yield improvements, these treatments may pay for themselves over the longer term.

No measureable changes in soil condition as a result of adding 2 t/ha compost were measured in 2013 and 2014 that would add value to the long term profit of this site.

Machinery used for applying compost caused some compaction and due to the dry post-sowing conditions, crop germination was very patchy. The trial site experienced significant moisture stress early in the season and may not be representative of seasons experiencing an average or wetter start.

The SOI phase signal for April-May (available on the last day of May) and subsequent monthly phases can provide useful information on the likelihood for rainfall for the rest of the season. It can be a very useful tool for assessing the risk of topdressing nitrogen fertiliser (especially if it is used in combination with other indicators such as potential of the crop; decile trend and stored soil moisture).

• Zinc efficient and inefficient wheat cultivars were grown in soil cores in the glasshouse.
•  The calcareous soil had low micronutrient levels and high pH and boron.
• Although cultivar Gatcher produced 47% more dry weight of tops and double the root length density of cultivar Excalibur at maturity, cultivar Excalibur was much more efficient in terms of zinc uptake by roots and sevenfold more efficient than cultivar Gatcher in partitioning zinc to grain.

• Poor growth of flax observed on "Bay of Biscay" (black clays) in Auburn area of South Australia.
• But soil type patchy through paddocks.
• Agricultural zinc sulphate was cheaper and as effective as calcined zinc in correcting the problem.

• Across three years addition of trace elements and fluid fungicide in-furrow did not provide increases in emergence, tillering or final yield - although this contradicts what other farmers have reported.
• Liquid N at sowing can improve crop emergence and early vigour, especially under dry conditions .
• Full liquid systems did not provide a profit benefit (due to higher input costs) even where they did provide increased yield which was not in all years.
• Recommendation most likely to provide higher returns for this area will be an in-furrow fertiliser system that incorporates some elements of liquid nitrogen and phosphorus fertiliser ,trace elements, fungicides and granular phosphorus and nitrogen fertiliser.

Cu fertiliser greatly increased yield from 0.6 t/ha to 1.60 t/ha.  

In general oxide source was equal to or superior to the sulfate source in wet mixes. In dry mixes in the same trial Cu oxide was only 66 % as effective as the sulfate.

A recent development in diagnosing Cu problems by a technique of using the youngest fully emerged leaf. Copper concentrations of less than 1.3 ppm (mg/kg) in the yougest fully emerged tissue , suggest that soil Cu deficiency will reduce grain yield .

The tissue testing technique was used on arange of Cu trila in the district to confirm the method (UWA Lonragan, Robson , Snowball)

For the first time it has been possible to distinguish crop damage caused by Cu deficiency from that caused by other factors such as frost, drought and root rots which produce similar symptoms.

Cu fertiliser greatly increased yield from 0.6 t/ha to 1.60 t/ha.  

In general oxide source was equal to or superior to the sulfate source in wet mixes. In dry mixes in the same trial Cu oxide was only 66 % as effective as the sulfate.

A recent development in diagnosing Cu problems by a technique of using the youngest fully emerged leaf. Copper concentrations of less than 1.3 ppm (mg/kg) in the yougest fully emerged tissue , suggest that soil Cu deficiency will reduce grain yield .

The tissue testing technique was used on arange of Cu trila in the district to confirm the method (UWA Lonragan, Robson , Snowball)

For the first time it has been possible to distinguish crop damage caused by Cu deficiency from that caused by other factors such as frost, drought and root rots which produce similar symptoms.

• Soil applied fertiliser was and better than liquid urea or UAN applied with standard spray nozzles to the crops leaves.
• Both urea and UAN are equally as effective when applied to the soil.
• Growers should select the nitrogen product that most suits their farming system in terms of logistics and cost.

• Fluid trace elements banded under the seed row is an effective system for delivering these nutrients to cereal crops.
• Rates of trace element application as banded fluids may be lower than for other seeding strategies and cheap sulphates can be used
• Mixes of trace elements as banded fluids are effective.
• Trial was not trace element deficient.

• No further yield benefit was measured from applying other nutrients (S, K, Mg) and trace elements (Zn, Mn, Cu) over and above that from applying nitrogen and phosphorus alone.

• Copper deficiencies have been reported but are usually corrected with fertiliser addition, however diagnosis can be a problem.
• Some evidence for boron deficiency on sandy dune soils in the Murray Mallee, upper south east and Eyre Peninsula, only a narrow range in soil B between deficient and toxic. Alkaline calcareous soils are known to contain toxic concentrations of boron.
• Molybdenum deficiency occurs on acid soils in the Mt Lofty Ranges, Fleurieau Peninsula, Clare Hills, Kangaroo Island, south-east and lower Eyre Peninsula. It has been recorded for legumes but not cereals.

• Only 31 per cent of the applied urea nitrogen (N) was taken up by the wheat crop in 2014. This low fertiliser use efficiency may be partly related to the season; unused N in the soil can benefit the following crop.
• In a decile 1 season, different stubble retention practices had no effect on microbial biomass and N supply potential (avg. 58kg N/ha).
• Labelling a wheat crop with 15N allows researchers to quantify the fertiliser use efficiency and trace the N from stubble to the subsequent crop.

• Occurrence of blackleg infection was generally low at Westmere in 2013.
• The ‘Rolls Royce’ treatment of Jockey seed treatment, Impact on fertiliser and two applications of Prosaro yielded significantly higher than the control (600 kg/ha difference).
• All treatments that received foliar applied Prosaro had significantly less infection at green bud compared to only seed or fertiliser fungicide or nothing.
• Prosaro’s ability to control blackleg is clear however yield results in a year with low blackleg burden make it difficult to distinguish between in furrow and foliar fungicide control.
   

• Triticale is very responsive to high inputs of seed and fertiliser.
• Adequate fertiliser is needed to achieve protein levels above 10%.
• In dry springs triticale yields are 10-15% below wheat, due to triticale’s longer grain filling period.

• Triticale tolerance of low manganese was much greater than for wheat or barley, but not as good as rye.
• Higher seen Mn in triticale varieties was correlated with greater yield.
• There was significant variation in manganese efficiency between triticale genotypes.

• N demand by crops in last year’s trials results was low due to the very dry finish to the season.
• There was no benefit from applying Twin N to wheat in this season.

• The trial was designed to test the capacity of TwinN to enable reductions in nitrogen fertiliser applications.
• The control treatments showed no statistical difference in yield between 0 and 50 kg/ha urea but a difference was seen between 50 kg and 100 kg/ha ureas.
• Yield from TwinN plus 75 kg/ha urea was not statistically differenent from that from the 100 kg/ha urea.
• No treatment effects were found in protein% or screenings%.

Following this year's trials results we are confident that UAN can have a role as an in-crop N fertiliser.

Best practice for using UAN at rates of up to 60L/ha when mixed with herbicides and fungicides:

• if using herbicides or fungicides not in this trial then always to a 'jar' test first for determining the physical compatibility: if white clouds or clear divisions appear, then the two may not be compatible;
• herbicides and fungicides mix better with UAN if mixed in water first;
• do not spray at temperatures over 25degrees C especially after flag leaf emergence because you don't want to scorch the flag leaf (!)
• do not spray when the Delta T is < 2, it appears that the leaf scorch is worst when humidity levels are high.

• The 2015 season was cooler than 2014 which affected how canola varieties developed and grain yields.
• Early sowing presents a good opportunity to improve canola water use efficiency and yields but variety selection is important.

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.

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

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.

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.

In a trial on Yitpi at Corack there was not yield or margin benefit from using flutriafol on fertiliser at either 400 or 800mL/ha rate, despite low level stem rust and yellow leaf spot infection in the top three leaves of the crop.

• 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.

• 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.

Precision farming tools such as EM surveys and yeild mapping can add greatly to our understanding of grain yield and quality variation across a paddock. The results of N fertiliser and sowing rates on Silverstar wheat demonstrated that:

• grain yield differences are determined by soil type.
• high sowing rates can contribute to lower screenings but does now guarantee lower screenings.

The larger scale trial work raised issues on how to interpret small scale plot work. There is a greater need for researchers and farmers to work together towards identifying and interpreting paddock variability, before large scale, and often costly, management practices are put in place. 

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).

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.

• Without this intensive mapping the paddock would have been either under or over limed and fertilised resulting in either a loss of productivity or a waste of fertiliser/lime dollars and possibly both.
• Whilst it’s economically beneficial to apply variable rate technology for a liming program, until more cost efficient soil testing methods are developed, the economic justification may not be there for soil nutrients.

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.

• 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.

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.

• The relative sensitivity to manganese deficiency is broadly : bread wheat (least), barley, durum wheat (most).
• The relative sensitivity to zinc deficiency is broadly: barley (least) bread wheat, durum wheat (most).
• With a very inefficient variety adding a micronutrient fertiliser may not be sufficient to overcome the deficiency.
• Special attention needs to be given to the micronutrient requirements of durum wheat especially where high rates of N and P fertilisers are used.

• 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.

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.

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 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'.

• 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.

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.

• 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.

• 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.

• The yield of wheat and barley was double on cultivated fallow compared to chemical fallow medic pasture.
• Cultivation is also known to reduce the numbers of nematodes.

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.

• 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.

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.

It is important to consider the seasonal risk posed by diseases when developing an appropriate disease management strategy. Avoiding susceptible barley and wheat varieties will significantly reduce the risk of grain yield and quality loss due to disease Both foliar and fertiliser fungicides can both provide effective disease management when applied to coincide with the critical development stages of disease epidemics.

Seed and fertiliser dresings and in-crop fungicides did not give a response in wheat in a drought year. Ventura and H45 yielded better than Diamondbird.

• Seed and fertiliser dresings and in-crop fungicides gave responses in wheat that were inconsistant.
• Stripe rust varieties gave less reponse.
• Generally the best response came from spraying at full tillering (Z31).

• Fertiliser dressings gave responses in wheat during 2008.
• There were no responses to in-crop fungicides.
• During the four year of the experiment, the best fungicide treametns have benn the seed and fertiliser treatments and the in-crop fungicide sprays at growth stage Z 39 (flag leaf emergence).

• Similar yields can be obtained using a number of combinations of seed and fertiliser.
• Low tiller numbers can be recovered by using light amounts of nitrogen.
• There may be opportunities to use much lower inputs and still produce high-yielding and profitable crops.

• Trial reveals that 70 plants per square metre (about 35kg seed) and 5-10 kilograms per hectare of phophorus represent the optimal target plant density and phosphorous input level for wheat.
• Similar yeild results can be obatained using a number of combinations of seed and fertiliser.
• Low tiller numbers can be recovered by using light amounts of nitrogen.

• Wheat responded to up to 12 kilograms per hectare of phrosphorus (P) without added nitrogen (N) and to 6kg/ha of phosphorus with added nitrogen.
• Higher fertiliser rates did not improve yield or tiller numbers.

Two years of trials at Forbes on low Zn soils show no indication of wheat response to Zn fertiliser. There is some evidence that Zn deficiency in wheat can be intensified by SU herbicides. However, the critical soil Zn levels needed to justify Zn fertiliser use in wheat grown on lower pH soils treated with SU herbicides is unknown. Fertiliser test strips over a number of years have an important role to play in determining potential Zn responsiveness.

• Nitrogen applied during stem elongation significantly improved grain yield and protein.
• The higher density crop produced greater yields for both row spacings.
• There was little difference in grain yield between the row spacings.

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.

• There was no yield response to increased P rates in any variety tested suggesting that adequate available soil P masked any purported difference in P use efficiency between varieties.
• However, there was a trend in that the grain yield of the variety Axe increased in response to higher levels of P in both the replicated and broad acre studies.

• Early sowing increased grain yields in all of the wheat varieties trialed, however, the size of the increase was dependent on the variety.
• Nitrogen application increased grain yield in the early sown treatments and increased grain protein especially in late sown crops.

Nitrogen use has resulted in great improvements in crop yield in favourable seasons.
In dry seasons too much applied nitrogen can result in haying-off and lower yields.
Good guidelines are now available for nitrogen use to reduce the risk of crop failure resulting from applying too much fertiliser nitrogen.
The critical factors are:
• Stored soil water (control summer weeds)
• Measure how much nitrogen is in the soil prior to sowing
• Calculate nitrogen requirement from the target yield
• Do not pre-drill more than 60 kg/ha of urea in the 350mm rainfall zone (100kg/ha in the 450mm zone)
• Split applications are safer
• Topdress with urea if the soil test indicates a need, the crop is healthy, and the outlook is for an average to wet season

30 years after application, water soluble P leaches to depth on grey sands but is still effective for the growth of deep rooted blue lupins.  On the one-hand, the citrate-soluble P in C-500 releases more slowly through time and so has a longer term residual effect than water soluble P. On the other hand, higher rates of C-500 are required than superphosphate to reach maximum yield when soil P levels are low.  It is less likely to leach and so pollute ground waters. If cheap enough, C-500 could be used as a maintenance P fertiliser.  Much work is still to be done on this trial site.

Calculating N supply in a highly variable climate is a difficult task and delivering split applications is attractive when aiming to minimise the risk of over- or under-fertilising.

• Canola grown in wide rows (50-60cm) yielded well enough to consider this row spacing as an option.
• Canola plants were able to compensate for being sown in wide rows - biomass similar to narrow rows.
• We may be able to reduce input costs, seed and fertiliser by refining the production package in wide rows.
• Wide rows offer benefits of reduced fuel costs at seeding, easy stubble handling and safety of IBS herbicides.

• Canola grown in wide rows (50-60cm) yielded well enough to consider this row spacing as an option.
• Canola plants were able to compensate for being sown in wide rows - biomass similar to narrow rows.
• We may be able to reduce input costs, seed and fertiliser by refining the production package in wide rows.
• Wide rows offer benefits of reduced fuel costs at seeding, easy stubble handling and safety of IBS herbicides.

• Canola grown in wide rows (50-60cm) yielded well enough to consider this row spacing as an option.
• Canola plants were able to compensate for being sown in wide rows - biomass similar to narrow rows.
• We may be able to reduce input costs, seed and fertiliser by refining the production package in wide rows.
• Wide rows offer benefits of reduced fuel costs at seeding, easy stubble handling and safety of IBS herbicides.

• The main difference in yield may have been due to poor tillage in the 500mm spaced crop.
• The entire crop was reliant on the soil nutrition from the pasutre as no fertiliser was applied to the paddock prior to and following seeding.
• Later sowing of the trial may have jeopardised the wide row's yield capacity therefore it would be encouraged that when considering sowing in wide rows early seeding is preferable.
• It may be noted that if nutrition was not a limiting factor for the 500mm crop, the water supply from the wide row may have increased yield to similar or better than that of the 250mm crop.

• Spring barley germplasm cv Planet following canola with an estimated 146 kg N/ha available soil mineral N (0-90cm) gave a small response to applied nitrogen fertiliser with yield maximised (9.74 t/ha) with 80 kg of applied nitrogen per hectare.
• The highest yield (10.1 t/ha) was achieved with an application of 240 kg N/ha; however, this was not significantly higher than the yield achieved (9.74 t/ha) when 80 kg N/ha was applied.
• No lodging was observed in this trial.
• When 200kg N/ha or more was applied grain protein was higher than 12.0% and grain was no longer classed as malt quality.
• There was a significant increase in final dry matter production associated with 80 kg N/ha in comparison to the unfertilised (14.83t/ha increased to 17.7 t/ha).
• At higher rates of nitrogen, the dry matter steadily increased to 20.8 t/ha at the highest rate of 320kg N/ha.
• Since there were no significant yield increases associated with higher N rates harvest index (proportion of harvest dry matter harvested as grain) decreased at higher N inputs, however the differences were not statistically significant varying from 51.8 to 42.3%.
• There was no statistical difference in nitrogen offtake in the crop canopy at harvest in the grain & straw between 200-320kg N/ha applied an uptake of 238-292kgN/ha assuming straw and grain was removed from the paddock.
• N uptake associated with applied N rates above 160N were not translated into higher grain yields but were associated with higher grain protein.
• N offtake in the crop canopy peaked at 292kg N/ha when 280kg N/ha was applied.
• Head number was significantly increased by nitrogen applied although there were no yield increases associated with head numbers above 840 heads/m2 in this trial.

• Lodging began in early October with the general trend being more lodging as the N rate increased but not necessarily as a lineal progression.
• The uptake of N by the crop did increase as rates applied increased. This resulted in higher total biomass but not necessarily higher grain yield. Of the two rates assessed, the uptake of applied N was approximately 45%.
• Highest yielding treatments were those that received 80 – 280 kg N/ha. 0 kg N/ha or the highest rate of 320 kg N/ha resulted in decreased yield.
• While 120 kg N/ha did not see a yield increase over the 80 kg N/ha treatment, it did see grain protein high enough to meet malting specification.
• As a general trend, higher applied N resulted in higher grain protein and lower retention. Using the yield results from the 120 kg N/ha treatment, the Nitrogen Use Efficiency was 30 kg N required per tonne of grain.
• WUE of the trial averaged 19 kg/mm.

• Barley yields cv RGT Planet of over 6t/ha were achieved in 106 days from sowing to harvest with no applied nitrogen.
• Yield was maximised with no addition of nitrogen fertiliser.
• At the highest rate of 240 kg N/ha, there was a significant reduction in yield (6.03t/ha) compared to where no nitrogen was applied (6.24 t/ha).
• There was no difference in grain yield when nitrogen application timing was varied.
• Grain protein increased as higher rates of N were applied up to 160 kg N/ha. Between 160 and 240 kg N/ha, there was no difference in grain protein.
• The grain protein was too high to achieve malt quality in all application timings and rates of nitrogen in this trial.

• There was no interaction between nitrogen rates and nitrogen timing in this trial.
• With moderately high soil fertility following canola (146 kg N/ha available mineral N (0-90cm)) there was no significant difference in grain yield at N rates between 80 – 240kg N/ha (identical result to Trial 1).
• Delaying nitrogen application to GS32 (second node) and GS37 (flag leaf visible) gave a significantly higher yield (9.95 t/ha) than applying nitrogen at sowing and GS30 application (9.37 t/ha).

• Delaying the nitrogen applications to the development window GS32-GS37 increased protein slightly and although the effect was not statistically significant the risk of not achieving malt quality is increased at higher N levels.
• Grain protein increased as higher rates of N were applied, at 160 - 240 kg N/ha, protein was above the maximum 12% required to achieve malt quality irrespective of N timing.
• There was no significant differences in test weight (data not shown), although it was a factor in some treatments not achieving a malt quality grade.
• N uptake in the crop at harvest indicated that over 200kg N/ha had been taken up in the crop.

Wheat, barley and canola were tested in 2018, and wheat and barley in 2019, representing a range of quality segregations. Trials were located close to Hyden, Kojonup, Jerramungup, South Stirling, Mt Madden, Munglinup, Gibson and Scadden and Salmon Gums.

The 2018 season was characterised by significant autumn rainfall and below average seasonal rainfall for most sites. The first time of sowing was seeded dry for most cereal and canola trials and the second sowing followed opening rains.

There was little evidence from the eight locations in 2018 to support the idea that the latest varieties differ in their response to increasing N and P inputs in wheat, barley and canola such that it could be exploitable by growers. Some interactions between variety and N and P nutrition were identified but responses were isolated and varied with crop and site. For example, significant interactions were measured for wheat yield at Gibson and protein percent at South Stirling; barley yield at Jerramungup, protein at Hyden, protein at South Stirling and screenings at Kojonup; canolayield at Gibson and oil content at Hyden.

In 2019 the Western Australian wheatbelt experienced a late start to the winter growing season and one of its driest. Data from the Bureau of Meteorology show all sites tested in 2019 experienced a Decile 1 season with well below average seasonal rainfall.

The 8 locations for wheat and barley in 2019 tested N rate and timing and supported the findings of 2018 with very little evidence to support the idea that varieties differed in their response to increasing N inputs. In fact, the opposite was true with the four varieties of wheat and barley tested responding in very similar ways for yield and grain quality.

The lack of consistent variety x fertiliser interactions in these environments suggests growers need only consider a crop and not specific varieties in their agronomic management.

N and P nutrition in 2018 and N nutrition in 2019 data supports current farmer practices of adequate basal nutrient upfront for the season, followed by post-emergent nitrogen as season and yield potential warrant.

Conclusions of this study are limited by the site-specific growing conditions and choice of varieties.

Take Home Messages

• Near perfect growing season for canola, provided ideal opportunity to assess the residual N feeding effect of the legumes.

• All legumes sown in 2016 – peas, lupins, sub clover and faba beans had similar starting soil N levels and soil water nitrate readings throughout the year which was reflected in similar grain yields inferring that all legume species were equal in terms of their N fixing capabilities.

• The average amount of N fixed by the legumes was calculated as ~86kg/ha.

• Growing adequately nodulated legumes can give rise to a ~1t/ha canola yield advantage compared with a non-legume.

• Linseed used more moisture, from a greater depth, than the faba beans in 2016. Resultantly more moisture was extracted by the canola crop sown on the faba bean stubble in 2017, and yet there is still more  residual moisture left.

Similar to trials undertaken in previous years, the fungicide trials undertaken in 2005 indicated there was no fungicide activity on Yellow Leaf Spot (YLS) when applied early post emergent (GS13 – three leaf stage). Fungicides applied to fertiliser or as a foliar application did not reduce the level of YLS in the crop and showed no yield benefits. Zincsol® applied to crops in paddocks which have had a good zinc fertiliser history also showed no benefit in reducing YLS pressure. After several years work the BCG conclude that spraying fungicides for YLS is not a successful practice.

Similar to trials undertaken in previous years, the fungicide trials undertaken in 2005 indicated there was no fungicide activity on Yellow Leaf Spot (YLS) when applied early post emergent (GS13 – three leaf stage). Fungicides applied to fertiliser or as a foliar application did not reduce the level of YLS in the crop and showed no yield benefits. Zincsol® applied to crops in paddocks which have had a good zinc fertiliser history also showed no benefit in reducing YLS pressure. After several years work the BCG conclude that spraying fungicides for YLS is not a successful practice.

• An increase of wheat grain yields released between 1957 and 2007 was found.
• Yields have increased because of improved harvest index, more biomass at flowering, and increased grain number.
• Nitrogen is critical in allowing each variety to reach its potential through increasing growth rate between stem elongation (GS31) and flowering.
• WUE has improved over the 1957-2007 timescale through increased yields, not greater extraction of water.

• APSIM simulations, accessed through the Yield Prophet web interface, were evaluated for their ability to forecast nitrogen fertiliser responses at the canopy management trial in the Wimmera.
• Yield Prophet accurately simulated crop yield and protein for a range of nitrogen fertiliser application rates and timings.
• Yield Prophet was able to estimate likely nitrogen fertiliser responses and dollar returns during the season.
• For accurate simulations Yield Prophet requires good soil characterisation data (crop lower limit, drained upper limit and bulk density) and pre-sowing measurements of soil water and available nitrogen.

• There have been findings that Wyalkatchem is generally more frost prone than other varieties.
• If you are cropping a high frost risk area, good management would suggest minimising input costs (e.g. fertiliser) in these areas.
• Due to the large LSD there were no statistically different treatments. However there seems to be a trend that the lower seeding rate improved yield.
• There was no significant yield difference between retaining stubble and burning the stubble at both seeding rates.

• Zinc in shoots at tillering was much higher in plants supplied with fluid phosphorus than with granular phosphorus.
• Given that in both sets of treatments zinc was supplied as zinc chelate at quite a low rate (0.75 kg zinc/ha) in a fluid below the seed row (except in fluid treatments it was mixed with TGMAP) these results suggest that mixes of trace elements with NP fluid fertilisers may be a more effective technique for supplying trace elements to broad acre crops.
• Conditions in both trials were not zinc deficient for wheat production so the absence of zinc in fertilisers at seeding had no impact on the productivity of either wheat at either site, or on their response to phosphorus fertilisers.

• Wheat grain Zn concentration decreased with P fertiliser addition.
• Wheat grain Zn concentration was lower after canola than after either linola or clover pasture.
• Wheat receiving P fertiliser had lower mycorrhizal colonisation than that with no P added.
• Wheat after canola had lower mycorrhizal colonisation than that wheat after linola or clover pasture.
• It was hypothesised that Zn uptake was reduced where mycorrhizal infection was lower.