High stubble loads appear to increase frost damage by reducing the amount of heat radiated from the soil at night, leading to lower canopy temperatures and greater frost severity, duration and damage.

Preliminary results have shown that the removal of stubble can reduce frost severity and duration. However, this does not advocate the complete removal of all stubble on farming properties. The removal of stubble may be beneficial in low lying frost prone areas of paddocks.

• Since soil moisture was not limiting, and a soft finish to the season was observed, sowing date trials at Minnipa in 2010 showed no differences in yield between stubble treatments under these conditions.
• This trial will be repeated in the same environment to validate across seasons.

• In 2007, herbicides applied to burnt stubble were more effective than those applied to slashed stubble. In 2008, there was no effect of stubble management on efficacy or crop safety.
• All herbicide treatments gave adequate control ofryegrassin both years, but TriflurX® 1.5L/ha + Avadex Xtra® 1.6L/ha gave the best control in both 2007 and 2008.
• Improved control of ryegrass did not increase yield, and the most profitable treatments were the lower rates of trifluralin.
• Standing stubble substantially increased grain yield relative to slashed stubble (0.41 and 0.47t/ha in 2007 and 2008 respectively).

• Rainfall over the summer fallow period will cause nutrient leaching from stubbles.
• Stubble crop type determines initial value of stubble and what may be leached due to rainfall.
• It is important to consider other loss pathways such as microbial breakdown and volatilisation as well as leaching when calculating stubble nutrient value following the summer fallow period.

• In wet years, barley sown into cereal stubble can suffer badly from yellow leaf spot.
• In dry years, this is not a problem.
• However, the barley still performed better where the wheat stubble has been burnt.

• Cereal stubble should be burnt when sowing wheat, barley or canola.
• The smaller the cereal and canola seedlings do not thrive when grown in stubble.
• Larger seeded crops such as chickpeas and lupins performed best in stubble retained situations.

Temperature results from both sites have demonstrated that stubble loads above 2t/ha increased the severity and duration of some frost events. Analysis of results on yield and frost damage is ongoing and will be presented.

Temperature results from both sites have demonstrated that stubble loads above 2t/ha increased the severity and duration of some frost events. Analysis of results on yield and frost damage is ongoing and will be presented.

• In 2016, a Decile 10 season, stubble load had no effect on soil mineral nitrogen or soil water.
• The presence of stubble resulted in higher soil mineral nitrogen over the summer fallow period.
• Wheat yields were higher following peas or fallow than they were after wheat or canola in 2016.

• The combination of stubble burning and post-emergent use of a Group A herbicide has effectively controlled ryegrass in plots continuously cropped for 21 years at Condobolin.
• This combination worked well in both cultivated and direct drilled systems.

• The addition of sulphur increased wheat grain yield at both trial sites.
• Grain yield at the clay loam site was consistent for all of the sulphur rates, sources (gypsum and SoA) and application times tested
• In contrast, there was variation in grain yield for the sulphur treatments tested at the sandy dune location due to the poor nutrient holding capacity of this soil type.

Early vigour – no significant difference. 

NDVI, 3 September - no significant difference.

Yield – see results.

• Durum quality wheat was produced at Lubeck, although high soil N levels pushed protein levels above the maximum for noodle wheat. Milling wheat grown at the same site achieved H2 quality. There was no yield response to N fertiliser at sowing. This demonstration highlights the importance of careful paddock selection when producing specialty wheat.
• While it has been demonstrated that durum wheat can be produced in this part of the Wimmera, durum is a high risk option. A basic economic comparison highlighted the high penalty when downgraded to feed quality if durum specifications are not met.

Canola yields in low and medium rainfall regions of south-western Australia are inherently low and variable.  We have shown that although N fertilisation increases the yield of canola, the yield increases are often relatively low.  Nitrogen also reduces the concentration of oil in the seed of canola and the rate of decrease can be rapid in low rainfall areas. 

The combined effect of N on yield and oil, along with the current payment structure for high oil canola, results in uncertain economic returns from N fertilisation in low to medium rainfall areas. 

We found that 90% of maximum gross margin was achieved at an average nitrogen rate of 17 kg N/ha, and the first 10 kg N/ha gave a return on investment in N greater than $1.50 per $1 in 80% of occurrences (experiments x variety combinations).  The next 20 kg N/ha applied gave a return on investment in N of $1.25 for every $1 spent on N in 80% of occurrences, and further increases were most likely to breakeven. 

We have shown that while farmers should continue to plan to apply N onto canola within the first eight weeks, delaying top-up N until 12 weeks after sowing – when the canola crop is near flowering, is a viable second option which provides some level of risk management for canola growers in low and medium rainfall areas in south-western Australia.

• Wheat yield increased from 2.6 t/ha in controls to 3.2 t/ha in plots receiving the equivalent of summer rainfall decile 5 (50mm) or decile 9 (100mm) in a single event in February.
• Stubble treatments (bare ground control, standing 2 t stubble/ha, flat 2 t stubble/ha, flat 5 t stubble/ha) did not affect the dynamics of soil water nor grain yield.

• The presence of stubble did not increase stored soil moisture, regardless of the size and number of irrigation events.
• In 2010 additional soil moisture at sowing did not generally increase final grain yield.
• Additional soil moisture can increase crop demand and response to nitrogen.

• The benefit of summer weed control can vary across soil types and conditions.
• Conserving summer soil moisture is generally money in the bank and can prove invaluable when there is a dry finish, although the benefits seem to differ according to soil type.
• Higher glyphosate prices meansthat growers need to become more efficient when controlling weeds. Targeting weeds while they are young and fresh will help with reducing glyphosate rates. The addition of residual herbicides, such as Ally, will reduce the need for follow-up spraying.

• Sunflower yields were very low at this site in 2015–16, averaging 0.56 t/ha.
• Plant population affected plant measurements, with larger head diameters and 1000 grain weights resulting from lower populations.
• Hybrid selection also affected plant measurements. Ausistripe 14 had the longest arc length but the smallest head diameter. Ausigold 4 and Ausigold 62 had very similar plant characteristics.

• There were responses to Super Phos but these were difficult to assess due to uneven pasture growth, the presence of blue lupins and a high stubble load from 2009.
• Pasture cuts on 17 June measured a 0.6 t/ha dry matter response to 200 kg/ha Super Phos.
• There were no responses to Muriate of Potash (MoP) or lime. Late season responses were variable.

• Trials are underway investigating the effects of rotational grazing versus set stocking of stubble residues on surface cover and soil characteristics in arable paddocks.
• Early rain in 2014 disrupted the trial’s implementation but initial results on a stubble / self-sown pasture grazed in June indicated no difference between set stocking and rotational grazing on surface cover.

• From 2007 to 2009 field pea crops in the Hart district were sown in an even spread from early May through to June.
• The majority of crops were within 500 m of field pea stubble from the previous year.
• Blackspot was most severe in early sown crops adjacent to field pea stubble.
• There was a significant relationship between predictions of disease risk made by Blackspot Manager and the disease severity observed in these crops.

The Sustainable Land Management Demonstration Sites in the Mallee have been established to demonstrate improved farming practices through a better understanding of crop management and water use to reduce groundwater recharge and soil erosion.

• Test your soil- soil testing individual paddocks for nutrient status and plant available water at the start of the season allows you to determine the paddocks yield potential and requirements. Knowing this information at sowing can assist in making decisions throughout the season.
• Yield Prophet- the crop simulation model is a great tool for assessing crop risk and predicting potential yields.

• Yield Prophet- the crop simulation model- is a great tool for assessing crop risk and predicting potential yields.
• For renovating overgrazed perennial pasture paddocks, the sowing of cereals is a low risk strategy.
• Pasture establishment is extremely difficult in the Mallee in years with limited spring rainfall.
• Cereal biomass production may be greater by an order of 10 times than either perennial or leguminous pastures in the first year of establishment.
• Best pasture options for a June sowing in terms of biomass in the first year of establishment are either forage brassica or Italian Ryegrass

• Nuseed Diamond achieved 5 t/ha grain yield from early sowing (watered for germination on 12 April).
• The high yield of Nuseed Diamond was due to its high biomass accumulation and high harvest index. ATR BonitoA was the lowest yielding variety, largely because it accumulated less biomass than hybrid non-TT varieties.
• Split nitrogen application resulted in higher grain yield than all nitrogen applied at sowing or all nitrogen
delayed to the 8-leaf stage.

• Pioneer® 45Y88 (CL) was the highest yielding variety, averaging over 4 t/ha, with Nuseed Diamond and Pioneer® 45Y25 (RR) also achieving high yields.
• Sowing on 5 April resulted in higher grain yield, reduced lodging and lower oil content compared with sowing on 26 April.
• A plant population of 35–56 plants/m2 resulted in higher grain yields than populations of 18 plants/m2 or 68 plants/m2.
• Applying 200 kg N/ha resulted in higher grain yields than 150 kg N/ha when the soil available nitrogen (N) at sowing was 64 kg/ha. Nitrogen rates above 200 kg N/ha resulted in no extra yield.
• Increasing N application rates above 200 kg N/ha reduced oil concentration.
• Crop lodging increased with plant populations above 35 plants/m2 and N rates above 150 kg N/ha.

• Correct varietal selection and optimal agronomic management can result in irrigated wheat yields of over 10 t/ha.
• LongReach CobraA, LongReach TrojanA and BeckomA were the highest yielding varieties.
• Delaying nitrogen fertiliser application by applying the greatest amount at booting was shown to improve grain protein concentration and reduce lodging compared with applying more nitrogen at sowing.
• A plant population of 120 plants/m2 was shown to yield more than higher plant populations whilst also minimising lodging.

• Annual ryegrass (ARG) establishment and seed head numbers increased significantly under the faba bean herbicide strategies used in 2016
• There were no significant differences between herbicide strategies in 2016, with the legacy of past years’ management strategies not creating any difference in yields this year
• Over the five years of the trial, RT Canola in 2014 was been the best option to maintain ARG seed head numbers
• ARG seed head numbers increased by 35% in 2016 following the high cost weed strategy (strategy C) in combination with HWS prototype mill
• ARG seed head numbers increased by 148% (low cost, strategy A) and 171% (mid cost, strategy B) in 2016
• Effects of pre-harvest desiccations in 2016 will not be evidenced until emergence in 2017 

• Substantially better brome control and seed set reduction is possible by using pre-emergence options other than trifluralin.
• The costly Sakura+Avadex treatment is likely to be the most effective.
• Consistency of performance of all pre-emergence herbicides for brome remains a problem
• On-row seeding on non-wetting sand showed that it can substantially improve early crop emergence.
• One reason for this is the likely wetter surface soil in rows at time of seeding.
• Seasonal conditions such as the long-wet season of 2016 will affect efficacy of both pre-emergence herbicides and the impact of additional crop competition on brome seed set suppression.
• Maintaining low seedbanks and having alternative options for weed seed control when faced with a risk of ‘blowouts’ in brome seed set is important given the chance of particularly poor control in some seasons.

In this trial we observed no response to the non-nitrogen test products, either on the low or high fertilizer at seeding treatments.  However we cannot say that they will not work under other site, season and management conditions.  Unfortunately the promoters can rightly say that we did not give their product the best opportunity to perform and so it was an invalid test.

Such a reply has implications for the promoters rather than the testers. The promoters have an obligation to state under what conditions they expect their product to work and those conditions  have to be readily recognized by potential local users. It is not good enough to list a range of processes which the product “improves” or even to quote circumstances from elsewhere where the product has worked. Any new product (and agronomic practice for that matter) has to be  extensively tested under local conditions so that the promoters can say what the chances of success are if used by local growers.

We, the testers are able to state that the product did not work under our conditions and in the Popper sense of “falsification” have disproved any statement about how generally useful the product might be. That is, 100% of our observations say it does not work, but that is hardly useful. We could have had a drought year and nothing would have worked. We could have been wiped out by      frost or we may have chosen a site with the wrong levels of fertility. We did not test across a full range of conditions and so have too limited information for invalidating the all claims made for the products. This problem is equally true for validation by the product developers.

Products MUST be tested across a wide range of local conditions before it can be promoted with confidence to the broader agricultural community.

In short, any new product (or agronomic practice) requires a major investment in validation trials which are ranged across the full set of management, site and season conditions experienced in the new environment. Otherwise, general promotion of those products should not be believed until such work has been done.

Forty per cent of all pasture and cropping sites had little or none of these beneficial species present. Of the sites where adequate populations of carabid beetles and earwigs were found, cropping paddocks were dominated by one subspecies of carabid (Rhytisternus) and the beneficial native earwig (Labidura truncate).

Agricultural activities such as cultivation, livestock farming, stubble burning and decomposition of crop residues cause greenhouse gases to be released into the atmosphere.

• Canola and peas only produced half the yield of wheat, but barley performed very well.
• Ryegrass is becoming a problem in wheat on wheat plots.
• Pastures performed well where seed reserves had been increased in 2011.
• All options had good soil moisture (40mm) at the start of the season.

Soil organic matter consists of a labile (non-permanent) and stable (humus) fraction. No-till increases the labile fraction of soil organic matter, but not the stable fraction. Additional nutrients will be required to ‘fix’ the labile fraction to humus.

• In 2015, two spring irrigations produced the highest wheat grain yield (7.61 t/ha), but one irrigation provided the highest water use efficiency (1.7 t/ML).
• Ponding irrigation water for 48 hours to induce waterlogging did not reduce grain yield in this experiment, but increased water use and reduced water use efficiency by 25%.
• If the number of spring irrigations is limited, it is important to find a balance between irrigating before significant moisture stress occurs and ensuring adequate moisture is available during flowering.
   

• Commercial viability has been difficult to demonstrate.
• Field trials demonstrated that the H Senor was able to accurately classify annual ryegrass in several broadleaf crops, including canola, faba bean, lentil and field pea.
• Other grass weeds such as brome grass and wild oats were also correctly identified as grasses in these crops.
• Broad leaf weeds were accurately classified in cereal crops, however this was more difficult due to the overlapping nature of the cereal crops at the time when the broadleaf weeds had emerged.
• Classification accuracy was lower for detection of grass weeds in cereal crops and broadleaf weeds in broadleaf crops, and these scenarios were not pursued for that reason.  

• Sowing date and varietal phenology both affected the exposure of canola to rain days and potential disease infection.
• Early sowing increased the level of pod blackleg infection.
• Early sowing increased sclerotinia infetion in the early flowering variety Hyola 575CL but not in the slower variety Pioneer 45Y88 (CL). 
• Grain yield was higher from the later sowing date (22 April) than the early sowing date (7 April).
• Grain yild was closely correlated to total biomass accumulation, which was greater from the 22 April sowing time than 7 April sowing time.

• Variety phenology and sowing date need to match to avoid plants flowering and podding during periods of severe frost. The highest yield in 2017 came from the 6 April sowing of the long season varieties Archer and ATR WahooA that flowered in early August.

• ATR Stingray and Nuseed® Diamond flowered earlier than the optimum start of flowering (OSF) date (28 July) from both the 6 April and 20 April sowing dates with significant frost damage incurred at both sowing dates.

• Canola varieties have the ability to recover from severe frost damage where soil water is not limited.

• Commercial viability has been difficult to demonstrate.
• Field trials demonstrated that the H Senor was able to accurately classify annual ryegrass in several broadleaf crops, including canola, faba bean, lentil and field pea.
• Other grass weeds such as brome grass and wild oats were also correctly identified as grasses in these crops.
• Broad leaf weeds were accurately classified in cereal crops, however this was more difficult due to the overlapping nature of the cereal crops at the time when the broadleaf weeds had emerged.
• Classification accuracy was lower for detection of grass weeds in cereal crops and broadleaf weeds in broadleaf crops, and these scenarios were not pursued for that reason.  

• Cereal stubble should be thought of as a source of C for microbes, not as a source of N for crops. In the Mallee under no-till systems, only 1-2% of the N requirement of wheat crops is derived from the previous wheat stubble.
• N tie-up in cropping soils is only a temporary constraint as the immobilised N will be released through microbial turnover, generally later in the crop season in spring.
• N tie-up by cereal residue is not just a problem following incorporation – it also occurs in surface-retained and standing-stubble systems.
• Management of tie-up is reasonably straightforward – supply more N (5 kg N for each t/ha of cereal residue) and supply it early to avoid impacts of N tie-up on crop yield and protein.
• Deep-banding N can improve the N uptake, yield and protein of crops, especially in stubble-retained systems.

• Each stubble incorporation prior to sowing lead to better weed control in the crop as we were able to create an early germination of ryegrass. 
• There was considerable difference in soil moisture and its distribution through the profile at establishement.
• Straw length at harvest was the biggest drawback in incorporating and establishment.
• Previous trial cropping areas, on other parts of the padock, still showed up the biggest difference in the crop's establishment.

• Varietal selection again proved to be the major factor in achieving higher wheat yields in the second year of experiments in irrigated wheat production at Leeton.
• CobraA was the highest yielding variety in this experiment but CorackA, SuntopA and the durum breeding line 280913 also performed very well.
• Correct nitrogen timing significantly increased grain yield, grain protein and significantly reduced lodging.
• Managing plant population also significantly reduced lodging

The practical implications of harvest weed seed control are a more resilient farming system with some insurance against further resistance evolution. The combination of effective herbicide use, plus harvest weed seed control techniques has been shown to reduce and maintain weed populations at very low densities. In cropping systems, low weed densities, regardless of their herbicide resistance status, allows flexibility in crop choice, seeding time and herbicide use. This flexibility provides growers with the capacity to readily adjust farming practices in tune with seasonal and market considerations.

• Grain and soil samples were collected from 13 field experiments where zinc deficiency had been identified as a problem.
• Zinc was applied in the field experiments at rates of 0-20 kg zinc/ha.
• Application of zinc (2.5 - 5 kg/ha) reduced grain cadmium concentraitons by up to half.

The results suggest using nitrogen and/or increasing sowing rates will increase drymatter available for grazing at late tillering but if grazed these treatments will have a positive impact on grain yield.

• Soil mineral nitrogen (N) values were low across all sites, which was indicative of the wet seasonal conditions and high nitrogen losses.
• There were no significant differences in mineral nitrogen values between the stubble treatments due to high variability (likely due to transient waterlogging across the sites).
• The project has been extended to enable the research to be repeated during 2017.

• While significant differences in mineral nitrogen (N) values were measured between stubble treatments, these differences were small and unlikely to elicit a plant growth response.
• No consistent trends were observed between trial sites.
• Delayed plant growth and development under no-till stubble retained (NTSR) systems in the Riverine Plains region is unlikely to be due to decreased mineral nitrogen availability as a result of immobilisation.

Grazing of the cereals up to growth stage 31 had no significant impact on grain yield but it did reduce the amount of stubble remaining post harvest.

• Nitrogen fertiliser management influences crop nitrogen uptake at defoliation and cotton lint yield
• Irrigation management did not influence crop nitrogen uptake at defoliation, but significantly influenced cotton lint yield.
• The apparent nitrogen fertiliser recovery was 46% where the optimum fertiliser nitrogen rate was applied
• Seed nitrogen concentration and nitrogen removal was influenced by nitrogen fertiliser application rate, but the effect was not consistent with rate.

When canola was sown into wheat stubble in an east-west direction, long stubble (42cm) significantly reduced photosynthetically active radiation (PAR) and reduced true leaf number up to mid-winter.

Although there were trends suggesting a reduction in dry matter (DM) production at the yellow bud stage (GS3.7) as a result of increasing stubble height, the differences were not statistically significant.

The average canola yield of the trial was 1.58t/ha with no significant differences in either yield or oil content due to stubble height of the previous wheat crop.

The results mirror a trial conducted at Dookie, where yields in long stubble were 3.70t/ha and 3.75t/ha in short stubble. At this site there were significant reductions in DM production early in the season in the long stubble treatment.

For farmers who have not yet reached this stage of herbicide resistance it is imperative that alternative control practices to herbicides are put into practice.

• While machinery ownership and management has its complexities, being aware of some of the aspects that directly impact upon its economic efficiency is a step in the right direction. Consideration of work rate efficiency and timeliness versus over-capitalisation and ultimate returns achieved by the system is very important.
• The Farming Systems Project has identified that the cost profile of the different farming systems from most to least costly is, Fuel Burner, Hungry Sheep, Reduced Till and Zero Till.

• Stubble rentention increased the severity of frost events in experiments over two years
• There was no difference in floret sterility due to stubble treatment, but grain yield was highest where stubble was removed by burning. 
• Stubble rentention reduced the amount of heat stored in the soil during spring. With less heat stored there is less capacity for energy release at night to buffer against frost damage.
• Consider management strategies that avoid frost (e.g. crop choice, sowing date, variety choice) where high stubble loads are retained at sowing. 

• The combination of Triazine Tolerant (TT) and Roundup Ready (RR) herbicide provided superior control of ryegrass and wild radish over individual chemistry treatments.
• Canola is an important rotational winter crop however, with increasing herbicide resistance across multiple chemistries in WA, growers are experiencing increasingly limited options with the current herbicide tolerance technologies available.
• Hyola RT® Technology allows the combination of strong knockdown and residual broad-spectrum herbicides from different herbicide groups and modes of action, targeting a wide range of weed species.
•  Hyola RT® will provide an important role in addressing the increasing Clethodim resistance problem.
• RT® dual herbicide tolerant Hybrids have now demonstrated their value as a new competitive integrated weed management (IWM) tool, also providing increased convenience and flexibility of in-crop weed control.

• The application of N increased yields of all cereals grown on a wheat stubble.
• The application of fungicides controlled leaf diseases in wheat and barley, and increased the grain yield of wheat.

• Early sowing of barley may be an effective way of controlling ryegrass growth and limiting seed set.
• Results in wheat are more variable than for barley: at Wanilla, mid-May seemed the optimal time of sowing to reduce ryegrass with less effect obvious at Yeelanna.
• Higher seeding rates also followed the same trend, with little ryegrass suppression benefit seen in wheat but a benefit evident in barley.
• Increasing seeding rate did not improve wheat yields significantly however barley (Fleet) did seem to benefit from higher seeding rates when sown late (mid-June).

• Early sowing of barley may be an effective way of controlling ryegrass growth and limiting seed set.
• Results in wheat are more variable than for barley: at Wanilla, mid-May seemed the optimal time of sowing to reduce ryegrass with less effect obvious at Yeelanna.
• Higher seeding rates also followed the same trend, with little ryegrass suppression benefit seen in wheat but a benefit evident in barley.
• Increasing seeding rate did not improve wheat yields significantly however barley (Fleet) did seem to benefit from higher seeding rates when sown late (mid-June).

• TOS1 was sown in mid May and established well.
• TOS2 was sown late May but did not emerge until late June.
• TOS3 was sown late June and emerged a few days later.

• We observed no significant differences in grain yield (GY) between any treatments due to low yield potential and reasonable soil nitrogen (N) levels at seeding.
• Timing of N application had no effect on GY. This is consistent with last years’ results at Wubin.
• Canola oil percentage decreased as N rate increased. High rates of N reduced oil significantly, consistent with last year at Wubin.
• The higher the rate of N the more rapidly oil percentage reduced, consistent with last year at Wubin.
• Gross margins (GM) decreased as N rates increased; all GM figures are negative due to poor GY, however, Sturt performed better than Pioneer 43Y23RR due to the higher seed costs associated with Roundup Ready (RR) seed.

• There were significant differences in grain yield (GY) between treatments (N kg/ha and timing), however, GY was particularly low in all treatments. 
• Total nitrogen (N) increased GY significantly up to 30kg N/ha.
• Canola oil percentage decreased as N rate increased. High rates of N reduced oil significantly.
• Applying N late (12 weeks after sowing (WAS) reduced canola oil percentage, however, not significantly.
• Gross margins decreased as N rates increased, but all gross margins (GM) were negative due to poor GY. Sturt had better gross margins than Pioneer 43Y23RR due to the higher seed costs associated with RR seed.
• Pioneer 43Y23RR produced higher GY at all rates and timings of applied N other than 10N seeding and 20N 12WAS.

For a full list of take home messages please see the attached trial report.

Large plot sites run by TOPCROP groups across the state generated many opportunities for discussing and fine tuning nitrogen management in canola. The season was the main factor influencing yields and gross margins. Nitrogen application of about 10-20 kg/ha for the Mallee and 10-50 kg/ha for the Wimmera gave best yields and gross margins at most sites in a difficult season.

• Field peas yielded significantly higher then both lupins and vetch.
• Field peas and undersown barley had significantly higher gross margins than lupin and vetch.
• In terms of gross margins there was no significant difference between field peas/undersown barley, undersown barley/vetch and lupins/vetch.
• When choosing to grow a pulse crop the following management issues are critical: time of sowing, paddock selection, species selection and disease and pest management.

• 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.

• The industry should begin to work with specialist organisations such as the Australian Institute of Company Directors (AICD) and Family Business Australia to provide regionally available training.
• • Continue to develop information sheets and meeting templates that provide support to farm businesses establishing an advisory board.

• 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.
   

A thorough understanding of trifluralin application techniques can be the difference between poor and excellent ryegrass control. It can also help achieve target plant establishment. This demonstration showed an increase in ryegrass control when up to 3L/ha trifluralin was applied. Rates above 3L/ha trifluralin did not result in additional ryegrass control. The influence of water rates was minimal due to the lack of stubble residue which shows that water rates of 50L/ha are acceptable in situations where there is very little residue from the previous crop.

• Winter habit canola has been successfully sown in spring, grazed over summer and harvested for grain in 2012, 2013 and 2014.
• Establishing canola in spring means larger, more resilient plants in autumn with less impact from slugs and waterlogging.
• Forage value comparable to commercially available dedicated forage rapes over summer and autumn with added benefit of oil seed production.
• Grazing management and timing of stock removal is proving to have an impact on grain yield.
• Vernalisation means winter wheats have the potential to be used in the same way.
   

• Winter habit canola has been successfully sown in spring, grazed over summer and harvested for grain in 2012, 2013 and 2014.
• Establishing canola in spring means larger, more resilient plants in autumn with less impact from slugs and waterlogging.
• Forage value comparable to commercially available dedicated forage rapes over summer and autumn with added benefit of oil seed production.
• Grazing management and timing of stock removal is proving to have an impact on grain yield.
• Vernalisation means winter wheats have the potential to be used in the same way.
   

Field observation suggests the 50% UAN solution produced a better stubble cutting action than water alone.

A network of soil moisture probes and Yield Prophet sites has been established across the Esperance, Albany, Kwinana East and Kwinana West port zones with the aim of providing public access to real-time soil moisture and weather data and periodic Yield Prophet reports to aid in-crop decision making, with particular reference to top-up nitrogen decisions.

Growers and agronomists have commented that the sites provided useful supporting information when making top-up nitrogen decisions, with the soil moisture probes providing additional confidence in the model’s output. Continuation of the Yield Prophet sites and soil moisture data recording and analysis will continue in 2015 across the Esperance/Albany and Kwinana East port zones, with the aim of further refining the sites to improve their accuracy and providing access to Yield Prophet and soil moisture information in a more user-friendly format.

Growers and their advisers in the area are more familiar with soil water relations, N dynamics and variation of yield potential in relation to soil types and season. Their integration into Yield Prophet reports has been demonstrated. This should lead to some commercial adoption of Yield Prophet and other crop decision support systems for better management of crops leading to increased profitability through management of seasonal risk.

• Barley leaf rust (LR) was observed on barley regrowth in the lower Great Southern and South Coast of WA in the summer/autumn of 2016. This contributed to the first observations of infected barley crops in the region in July 2016. All barley varieties including those with Adult Plant Resistance (APR) were under severe disease pressure and responded to application of fungicide.
• The high levels of LR in 2016 and the possibility of barley regrowth in autumn 2017 means a significant LR risk for the 2017 season and fungicide programs for APR varieties should be considered.
• LR is a social disease and all growers should be proactive in eliminating the volunteer barley green bridge. To minimise early onset of LR, the regrowth barley should be eliminated at least 4 weeks before seeding.
• Star of Bethlehem (an alternate host) should be sprayed to eliminate the likelihood of new pathotype developing in the region.
• Selecting varieties with adult plant resistance genes will reduce grain yield loss. However, performance of these varieties against LR is influenced by seasonal weather, time of disease onset, crop agronomy, and is hard to predict season to season. Depending on the LR pressure in the crop they may need early foliar fungicide intervention to reduce development of disease on plants during the growing season.
• Oxford possess two partial resistance genes (Rph20 and Rph24), and under high LR pressure application of foliar fungicides increased yield up to 64 per cent.

• 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.

• Slugs are a major pest for emerging canola crops in the high rainfall zone (HRZ)
• Detection across large areas is difficult from the ground
• Remote plant counts can be produced using images collected by drones
• Information can be returned to the grower within five days
• Only two out of every five days had suitable flying conditions, causing image collection to be delayed

• 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.
•  

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.

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. 

•  Yields were significantly higher under narrow row spacing, but sowing direction had no influence on yield.
• Weeds had a significant effect on yield, but the scale of yield penalty (t/ha yield loss) did  not alter with row spacing or sowing direction in 2015.
• Weeds established faster where row spacings were wider, however by late tillering, all treatments had similar weed numbers and biomass levels.

• Yields were significantly higher under narrow row spacing, but sowing direction had no influence on yield.
• Weeds had a significant effect on yield, but the scale of yield penalty (t/ha yield loss) did not alter with row spacing or sowing direction in 2015.
• Weeds established faster where row spacings were wider, however by late tillering, all treatments had similar weed numbers and biomass levels.

• 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).

An analysis of the soils PAWC needs to be conducted to determine yield potential of the soil types analysed to draw meaningful conclusions from these results.

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.

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.

• See discussion from trial L12.

Very little yield data is available for many of the crop species from the 2006 season. Furthermore, for some crop species, notably chickpeas, seed production was severely disrupted by the drought and the release of some of the newer varieties has been delayed by a year.

• Results indicate that herbicide management practices may need to be slightly modified in many instances for new ascochyta blight resistant chickpeas to maximise the yield benefits of these new cultivars.
• For field peas and lentils, each of the new cultivars tested performed similar to or better than current cultivars in terms of their herbicide tolerance and/or yield.

Trials were sown at Birchip to assess the relative tolerance of new field pea and chickpea cultivars to a range of commonly used herbicide treatments. Results indicate that the new varieties of field pea and chickpea perform similarly to commonly grown cultivars.

• Results indicate that management practices will need to be slightly modified in many instances to maximise the yield benefits of these new cultivars.
• For example, the new pea variety Kaspa should generally be sown slightly earlier and at higher density than the traditional cultivars Parafield and Dundale.

• Velocity and Precept selective herbicides are based on a new active pyrasulfotole.
• This is a new mode of action on broadleaf weeds in cereals in Australia (Group H).
• Velocity and Precept showed excellent crop safety.
• Broad spectrum and reliable broadleaf weed control.

• 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.

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.