These grower scale on-farm soil amelioration demonstrations have been managed by the growers according to standard practice. Both soil types were highly water repellent and the amelioration treatments have generally improved establishment but have probably had an even bigger impact on crop vigour. While it is possible to improve establishment, water and nutrient use efficiency and crop productivity using these techniques it is important to recognise that other constraints such as poor water and nutrient holding, soil acidity and compaction can still limit the yield potential of these soils. Pale sands which overly a clayey gravel or clay base within the top 1 m often have greater potential than the very deep sands.

While incidence of root rot was high (83-95%), the disease severity was low on the trial site ranging from 14.3 to 19.5% for treatment averages; many plants had a low level of root disease. Distinct patches were not evident in the trial.

Despite low levels of disease severity observed in the trial and only minor treatment effects on root rot, two in-furrow treatments were found to significantly improve the yield by more than 0.24 t/ha compared to the Untreated control. These were the granular fertiliser treated with Uniform® and the split application of Uniform® above and below the furrow.

In a site with a moderate rhizoctonia disease risk, as indicated by PreDicta B, the majority of plants had root rot however severity was low and patch development did not occur. Under low disease pressure, the Uniform treatments as a whole were able to provide a small reduction in disease incidence which subsequently resulted in yield increase from two treatments. Under higher disease pressure these products can be included as part of an integrated management approach for rhizoctonia.

One way ploughing slightly improved establishment, head numbers, biomass production and yield but is not a viable long term solution for the severe non wetting on this soil type.

Deep ripping and spading improved head numbers by over 60% and biomass production by 87% compared to the control.

Grain yields were improved by over a 1 t/ha and gross margin by about $200/ha when treatment costs were amortized over 5 years in the combined ripping and spading treatments.

EverCrop research reported in this and previous Crop Updates (2010-2014) has built up a sound knowledge base on the viability, performance and economics of pasture cropping and companion annual legume based systems for fragile soils in the Northern Agricultural Region that are marginal for continuous cropping. Collectively, trials at Mingenew and Dandaragan over the past two seasons (2013 & 2014) have demonstrated that subtropical perennial grass pastures lift the overall productivity of deep sandy soils, extend the period of available green feed, convert summer rainfall into feed, reduce the winter and summer weed burden, and increase ground cover.

It is critically important to sample soil pH to depth prior to investing large sums in lime application and incorporation. Typically it has been found that on sandplain soils the yield benefit of one-off deep cultivation or deep ripping is large enough to cover the cost of the tillage in the first year so the subsequent productivity benefits associated with more rapidly fixing the soil pH by incorporating lime can be realised sooner. Other factors such as water repellence, herbicide resistant weeds, subsoil compaction, wind erosion risk and soil type will impact on the choice of incorporation implement used.

This trial was sown early in May, however despite this relatively early sowing date the longer maturing varieties did not perform significantly better than mid maturing varieties. 

For further information please see attached trial report.

• Serradella, both French and yellow, produced large biomass and pod yields at Warradarge by taking advantage of late rains.
• There was greater budworm damage to seed in French serradella compared to yellow serradella.
• Early maturity serradella did not significantly decrease seed loss to budworm predation.

• Trial sowing at 11 June was later than optimal but plant growth was showing strong response to nitrogen (N) and some response to potassium (K) at 28 August.
• By harvest, Mace wheat showed significant grain yield response to nitrogen application but potassium response had moderated.
• No significant differences were seen from Cu application.
• Late sowing decreased yield potential from the start. Harvest yields ranged from 2 to 3 t/ha, with maximum yield and $/ha return at 80 kg N/ha and 12.5 kg K/ha.

Using an effective knockdown with broad spectrum pre-emergent grass herbicide like Sakura can deliver excellent weed control, yields and return on investment not just in the year of application but in following seasons due to a reduction in the seed bank when combined with a complete integrated weed management program across the farm.

• Soil inversion with a mouldboard plough, rotary spader and one way plough created equally patchy soil.
• The one-way plough created the most vertical redistribution of the surface 10 cm of soil.
• At least ten soil samples are required to gain a reliable mean for soil pH after inversion.

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

Funded by DAFWA and GRDC through DAW00204 ‘Delivering agronomic strategies for water repellent soils in WA’ and DAW00218 ‘Wheat agronomy systems profitability’. Thanks to LivingFarm for management of sites at Wickepin and Cranbrook. The provision of sites and support of growers Ray Falconer, Kyle Carson, David Stacey, and Kim Oliver is greatly appreciated. Thanks to Trevor Bell, Anne Smith, Stephanie Boyce, Paul Bartlett, Virginia Smee and Greg Brown for technical support. Thanks to West Midlands Group, Northern Agri Group, Facey Group, Gillami Centre and the soil wetter product manufacturers for ongoing support.

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.

• This trial clearly demonstrates the importance of matching clay application rate and incorporation method when clay spreading for water repellence. For subsoils with a clay content of about 30% using a rate of 100-150 t subsoil/ha incorporated with offsets to a depth of 120-150 mm was sufficient to overcome the repellence and given wheat yield increases of 11-18%.
• Alternatively subsoil application rates of 250-350 t/ha are probably required if the clay is to be incorporated to 250-300 mm with a rotary spader and this gave similar yield increases of 11-14% on what is a better soil type with higher inherent yield potential.
• The main benefit of higher clay application rates and deeper incorporation seemed to be in the canola year, although more seasons with canola need to be assessed to confirm the validity of this finding.

• Soil pH results after liming and tillage treatments were applied was found to be quite variable and more sampling needs to be done before pH results can be quoted. Soil loosening indicates that only the deep tillage techniques were likely to incorporate lime into the deeper 20-30 cm acidic layer.
• This trial highlights the importance of measuring subsoil pH levels and applying sufficient rates of lime to prevent and correct subsoil acidification. Where tillage treatments are used to incorporate lime it is important to understand to what depth lime will be incorporated and which subsoil layers need correction. It is intended to monitor this trial for the next few years to further assess the benefits of correcting subsoil acidification. Yield response to lime incorporation can increase over time as the untreated soil continues to acidify further and as lime has more opportunity to react and neutralize the acidity that is present.

• Our results suggest shifting investment from nutrients to lime and cultivation and maintaining profit in the first year for the 2 sites we ran is a feasible proposition.  However, this is dependent on the soil constraints and existing soil fertility.  In this trial, it appears that the cultivation response was driven by an increase in the mineralisation rate of organic matter. The incorporation of lime did not provide any yield benefit; while the rotary spader provided adequate mixing of the lime this had no impact on growth because soil pH was already above target levels.  The yield benefit from cultivation was enough to offset the cost of the cultivation and most of the lime application, and the net margin in the year of application could be improved by reducing fertiliser rates.
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• All treatments met Hindmarsh food grade parameters although loose smut was not tested for, which may have excluded the untreated from delivery due to its levels of infection.
• There was no significant difference in yield between treatments.

Many wheat varieties grown in WA already have the major gene for acid soil tolerance. In this trial several other acid tolerance traits are being assessed under field conditions to determine if they confer growth and yield advantages in addition to the major gene. If the traits do prove useful they can then be back-crossed into current well-adapted WA wheat varieties and ultimately become available for growers to use. In addition to these field trials, the project aims to identify molecular markers to facilitate the breeding process. The traits are likely to be beneficial in situations where soils are being limed to correct soil acidity but are not likely to help in highly Al toxic soils in the absence of liming. This trial and others like it will help determine under what soil acidity levels the traits are likely to be beneficial.

Acid soil tolerance in wheat is not a stand-alone solution for managing acid soils, rather it complements a liming program to ameliorate subsoil acidity. Subsoil at the site is acidic to a depth of at least 40 cm as demonstrated by the indicative site soil pH (CaCl2): 0-10 cm = 5.4; 10-20 cm =  4.2; 20-30 cm = 4.3; 30-40 cm = 4.3. Prior to the site being seeded 1.5 t/ha limesand was spread and this has lifted the topsoil pH to ~5.4 on average. More lime will need to be applied to the site to lift the low subsoil pH values.

• This trial demonstrated the attributes of true forage varieties in comparison to grain varieties.
• The practices adopted through graze and grain techniques have been invaluable to WA farmers and the products used in the trial can be adopted to increase production in mixed areas where livestock play an important part in farming systems through increased stocking rates and maintaining existing cropping rates.

• The one-off 2010 mouldboard ploughing treatment has resulted in yield increases of 1.0 t/ha or more for the past 4 seasons.
• The measured yield increases were partly a result of overcoming the water repellence by soil inversion and improving crop establishment.
• For further details please see attached trial report.

• Analysis of the results has not been conducted. The analysis will be distributed to the WMG membership when it is completed.
• Despite this, it is apparent that the data for the WMG trial does not show any trend to an improvement in pod numbers or yield for any treatment over the ‘Nil’ treatment.
• Of the other 2 sites, only the Mingenew trial showed a significant trend to increased pod numbers using ‘Lupin Bud‘ at the 6 leaf stage. Secondary pod numbers were also higher for all treatments compared to the Nil. This trial was not harvested.
• This trial should be repeated in 2014 to see if any conclusive claim can be made for the efficacy of ‘Lupin Bud’.

• The analysis of the results must take into account the Least Significant Difference (LSD) of 0.43 t/ha.
• The LSD of 0.43 t/ha indicates that Jenabillup was statistically better yielding than all varieties except PBA Barlock.
• All other varieties except Danja were not statistically significantly different in yield.
• The yield trend shows PBA Barlock was second highest yielding.
• While Jenabillup was the highest yielding variety, which is not unusual for this variety, it is not recommended for the WMG region as it is susceptible to Anthracnose.

• Powdery mildew severity at the WMG field site, maximum of only 7% leaf area affected on Baudin, did not allow differences between varieties to be seen, other than VS and S types (Baudin, Stirling, Vlamingh, Gairdner)
• Laboratory seedling tests indicate that some of the genes postulated to provide resistance to powdery mildew in some commercial barley varieties may be compromised by some powdery mildew isolates.
• Field screening of these varieties has shown that local differences in variety responses can occur but no widespread regional variation, or ‘breakdown’ in the field resistance of varieties to powdery mildew was observed in 2013.
• The field response of commonly grown varieties at the WMG site and across the seven trials generally reflected the resistance rankings published in variety guides.
• The differences identified in 2013 were of minor impact, or occurred in non-commercially relevant varieties, however they indicate that regional differences in variety response are possible due to variability within the pathogen population and continued monitoring is important to facilitate appropriate disease risk assessment and in-crop management.
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• 2 kg/ha seeding rate produced a plant density of 37 plants/m2; 4 kg/ha seeding rate 68 plants/m2
• Canola plant density had no effect on Nitrogen response
• 2 applications of 80Kg/Ha NS41 increased yield from 1.34 to 1.70 t/ha
• Plant test results showed low Boron (B) levels (about 14mg/kg) at the 6 leaf stage but there was no response to Bortrac 150 applied at early flowering.
• Large number of ryegrass plants, particularly in 2kg seeding rate plots.

• Average grain yield for the untreated control plots was 2.34 t/ha. Clay spreading and rotary spading gave the largest machine harvest grain yield responses of 400 kg/ha or more, mouldboard ploughing 270 kg/ha and one-way ploughing 180 kg/ha (Figure 1) compared to their nearest comparative control plots. Offset discs gave no yield response in 2013 but did have positive yield responses in previous seasons (Table 1).
• Grain protein levels averaged 11.4% for the untreated controls, clay spreading had 0.5% more protein and mouldboard ploughing 0.2% than their neighbouring controls (data not shown).
• Screenings for the majority of treatments averaged about 2.1%. Mouldboard ploughing was the only treatment to have significantly lower screenings of just 1.2% (data not shown).
• Total above-ground shoot biomass and head number was assessed using plant cuts (Table 1). Shoot biomass on average was increased by 95% (+4.3 t/ha) by rotary spading, 57% (+2.7 t/ha) by clay spreading and 47% (+2.3 t/ha) by mouldboard ploughing compared to the untreated controls. Head numbers on average were increased by 32% (78 heads) by spading, 22% (58 heads) by mouldboard ploughing and 17% (43 heads) by claying compared to the untreated controls.
• Observations made earlier in the season indicated that emergence of many plants in the untreated control areas was delayed and had fewer tillers than the earlier emerging plants in the many of the treated areas.
• The whole plant cut transects were taken across different soil types, rotary spading gave the best results on the poor pale deep sand at this site while mouldboard ploughing performed best on the better yellow sand (Transect 3).
• The net 3-year benefit and return on investment (ROI) has been determined for the first 3-years of the trial (Table 2). Estimated costs for the amelioration treatments are based on owner-operated and contract rates. Benefits associated with some of the treatments such as weed control for the mouldboard plough and reduced wind erosion for the claying treatment have not been included.
• The one-way ploughing treatment was the most affected by wind erosion in 2011, resulting in a loss in grain yield and income which has substantially reduced the net benefit and the return on investment for this treatment although the subsequent years have been profitable (Table 2). Of the other treatments rotary spading and mouldboard ploughing had the highest net benefit, driven largely by the large lupin yield increases measured in 2012. Claying also had impressive yield gains and substantial increases in income (Table 2) but the high cost of this treatment reduced the 3-year net benefit and return on investment relative to the deep cultivation treatments. Given that claying can show benefits for decades net benefit and ROI for this treatment should continue to improve over time and it still only took 2 years to cover the cost of the treatment. Offset discs had grain yield benefits for the first 2 years but showed no response in 2013 suggesting that the benefits of the shallow cultivation may have dissipated.