• There were no differences in wheat yield at Minnipa in response to stubble architecture, seeding position and nitrogen treatments in 2015.
• In 2015 plant establishment was reduced with cultivation and the addition of nitrogen at seeding compared to standing stubble cut low at harvest. The extra nitrogen applied at seeding also reduced the early dry matter.
• Removing and cutting stubble low decreased the Yellow Leaf Spot disease incidence and snail numbers compared to high cut stubble.
• Stubble management and seeding position had little effect on grass weed numbers.
• Overall at Minnipa, stubble management and seeding position have not impacted highly on crop production, weeds, disease and pests over two years with relatively high stubble loads in low rainfall farming systems.

• Barley sown into standing stubble yielded higher (between 0.15-0.33 t/ha) than cultivated or removed stubble in 2016.
• Standing stubble cut low (15-17 cm) resulted in the highest level of stubble being maintained into the following season.
• Maintaining standing stubbles may be the best option for yield and stubble carry over, but adequate nitrogen must be maintained.
• In 2014 and 2015 stubble management and seeding position did not impact strongly on weeds, disease or pests with relatively high stubble loads in a low rainfall farming system at Minnipa.

Standing stubble cut low (15-17 cm) resulted in the highest level of stubble being maintained into the following season.

Stubble management and seeding position had little effect on grass weeds.

Snail numbers were higher in standing stubble cut high (30 cm) and stubble removed had the lowest numbers.

Stubbles can be estimated using 1.3-2.8 times the grain yield, but it may underestimate the stubble in an average season following a good year, or after a very poor season.

In many low rainfall farming systems livestock are still a very important part of the farming system and the level of stubble carryover is reduced after grazing.

Stubble management and seeding position have not impacted greatly on crop production, weeds, disease and pests over three years with relatively high stubble loads for low rainfall farming systems.

Grower adoption of rotary spading and mouldboard ploughing in the West Midlands has been steadily increasing.

• This trial demonstrates the productivity and financial benefits that can arise from implementing rotary spading and indicates that the practice of deep ripping prior to spading appears to be worthwhile as not only does it remove obstacles and make spading easier it also appears to be a benefit to crop growth and productivity particularly in times of drought.
• Soil compaction was a significant constraint on this site and deep ripping alone has shown an advantage. Ideally controlled traffic system should be implemented after deep tillage to prevent re-compaction and loss of these benefits.

• Results too variable to determine effect of pH/lime on waterlogging.
• Trial will be continually monitored with greater changes in pH expected.

Adequate crop nutrition following summer crop is essential for optimised winter grain yield. Soils moisture was not limiting this season, therefore wheat responses were driven by crop nutrition.

Early termination of vetch resulted in higher soil N and soil water at sowing the following year compared with later termination timings of vetch. Wheat yield in the year following vetch was highest for the earlier termination timings of the vetch. Brown manure vetch had higher soil N and soil water compared to vetch taken through to harvest.

• Our results from the first year of the study show that the method used to manage soil water repellence had little impact on soil nutrient supply with the exception of phosphorus. The lack of grain yield response to applied P in the mouldboard and spading treatments suggest that soil phosphorus is more available in these soils, though is not clear whether this is due to the removal of the non-wetting constraint or mineralisation following tillage.
• The lower grain yield and harvest index in the spading treatment suggests that there was less soil water available late in the growing season. Further research is required to determine how these management practices, in particular inversion and rotary spading, changes fertiliser advice. The results of this work will be used to develop guidelines on if or how nutrition should be managed for crops sown on soils treated for water repellence.

• Winter cereal crop and variety choice can have a large impact on Pratylenchus thornei (Pt) population build-up within paddocks.
• Averaged across winter cereal entries, final Pt densities were 83% higher when sown in early May compared with early June.
• Final Pt populations were between 1.6 and 4.7 times higher in 14 of the 24 barley entries, the durum line 190873, and 12 of the 19 bread wheat entries when sown in early May compared with early June.
• The additional population build-up with early May sowing generally increased the risk level for yield loss in the following wheat crop from either low to medium, or medium to high compared to sowing in early June.
• Although earlier sowing can reduce yield loss associated with both crown rot (CR) and Pt, it does, however, appear to favour higher Pt population development in some winter cereal varieties, which could exacerbate negative consequences on following crops and/or varieties in the rotation.

• Concentrated chaff distribution had no significant impacts on nutrient stratification either horizontally or vertically across the landscape at three sites.
• Chicken litter applications appear to complement traditional chemical fertiliser applications by increasing P availability.
• All nutrients assessed were well above established critical levels and there was a tendency for all nutrients to be concentrated at the surface (0-5 cm) regardless of the known differences in mobility between N, P, K and S.

• In general for the bulk of the paddock in the wetter 2011 season there was little obvious difference in establishment between the knife point and winged point with paired rows seeder. However there were a several water repellent patches where establishment was poor for the knife point seeder but was much improved for the winged point-paired row seeder.
• Plant counts in these areas revealed that establishment was more than doubled from <100 plants/m2 to >200 plants/m2 through use of the winged point-paired row system in both the sandy gravel and pale deep sand soil types
• The advantage of improved furrow sowing as a tool to manage water repellent soils is it can be applied over all the repellent cropping areas, potentially for relatively low cost if only points and press wheels need changing on an existing seeder.
• For further results please see the attached trial report.

• Large range of cocksfoot cultivars trialled at three sites: Vivonne Bay, Parndana and Stokes Bay.
• Trials will be rotationally grazed .
• Persistence and productivity will be monitored over several years, subject to further funding.

• Lazuly and Porto cocksfoots are standout perennial grass cultivars, with Uplands cocksfoot showing promise for persistency in shallow dry soil environments.
• Gosse sub clover the standout annual legume, with Napier showing promise as a later cultivar. Trikkala sub clover still a good performer.

• Porto cocksfoot the standout perennial grass cultivar, with Uplands cocksfoot showing promise for persistency in shallow dry soil environments.
• Gosse sub clover the standout annual legume, with Napier showing promise as a later cultivar. Trikkala subclover still a good performer.
• Persistence and productivity will continue to be monitored over several years, subject to further funding.

• Knowing how much water is available at any point in time, and where the crop is using water from is extremely valuable when making management decisions.
• Potential water extraction depends not only crop type but also crop growth during the season.
• Correct data interpretation is critical for success when using soil moisture data.
   

• The impact of 13 different soil wetter treatments ranged from none to more than a doubling of wheat establishment.
• Grain yield benefits ranged from zero to 21% (or 0.22 t/ha).
• While higher grain yield generally correlated with better crop establishment, some treatments with low crop establishment were able to generate substantial yield responses, suggesting specific chemistries may promote later season effects.
• Combinations of some soil wetters interacted positively to maximize grain yield response.

Yield variability across the 22 focus paddocks in the project was moderate to very high. Yield variation needs to be managed to minimise the significant economic losses experienced in low performing parts of a paddock. We found very good correlations between soil EM38 maps, satellite imagery of crop vigour and crop yield at harvest. Utilising our knowledge of how the crops grew this season together with the precision farming tools available we will develop management plans in each of the focus paddocks to improve water use, yield and economic return.

In this article we summarise results of a recent study of ecological function of 60 patches of remnant native vegetation (“remnants”) in the Wimmera and Murray Mallee bioregions, the major dryland areas in Victoria’s northwest. We assessed soil and vegetation characteristics assumed to contribute towards the long term survival of remnants in the agricultural landscape.

• Profitability and risk are driven largely by a combination of soil type, associated enterprise mix, level of debt, machinery investment and land purchases.
• There is not best best farming system. Successful farming depends on factors within each system such as labour, soil type, rainfall and skills.

• Deep placement of organic and inorganic amendments increased grain yield by 20–40% for three successive years on a sodic subsoil at Rand.
• Deep placement of organic and inorganic amendments increased root growth and soil water use from the deeper clay layers during the grain filling-stage.
• Improvements in grain yield with deep placement of organic and inorganic amendments were associated with reduced subsoil pH and exchangeable sodium percentage, and increased microbial activity.

Please refer to attached trial report for results and discussion.

• EM38 surveys need to be calibrated through soil testing to identify areas with subsoil constraints.
• Simulated wheat yields using historical rainfall data demonstrated the effects of soil type and subsoil limitations on potential crop yields and recharge.
• Variable rate technology for fertiliser could optimise returns for paddocks with subsoil limitations.

• The paddock contained a population of effective rhizobia and so the number of nodules on lateral and taproots was not affected by the addition of different rhizobial inoculants.
• Improved soil nutrition did not affect dry matter production and nodulation.
• Grazing (simulated) reduced the total dry matter produced by the medic pasture, however the use of sheep would provide a more realistic assessment of grazing on DM production, nodulation and N2-fixation.

• Essential plant growth requirements including nutrients and water are influenced by the capacity of the soil to both store and supply these elements.
• Infiltration of water into soil and the ability for soils to retain water are processes fundamentally important for soil productivity.
• Management strategies that increase the rate of water infiltration into soils are likely to improve the potential of the soil to capture larger amounts of water.
• The rate of movement through the soil profile however, may be more important for crop production in terms of influencing the ability of plants to utilise this water.
•  

While water volume and droplet size were the focus of this study there are further measures that can be taken by the spray operator to increase herbicide penetration in stubble. In a recent paper by Gordon (2017) some of the strategies highlighted were:

• Reducing spraying travel speeds can generally improve the penetration into stubble and improve the evenness of the application.
• Narrower nozzle spacings can also be of benefit, provided the spray quality and boom height are suitable. 
• Alternately, many operators have plumbed machines with nozzle spacings to match the crop row width. Where nozzles are positioned in the centre of the inter-row gap between standing stubble lines, the nozzle height may be lowered to obtain an overlap close to the base of the stubble. This may improve soil contact and reduce interception by the stubble, provided spraying speeds and wind speeds do not excessive.

• Varieties in this trial did not show a response to extra applied nitrogen at this site which was in pasture for the previous 3 years. Possible reasons are low rainfall and plants being water limited and/or sufficient background levels of nitrogen available for the crop in this soil type. 
• In this season results showed a benefit in seeding early, providing greater growing season and therefore yield benefit, averaging 210 kg/ha higher. 

• Surface applied lime increased soil pH in the top 10 cm by 0.9 unit.
• Deep application of lime had a limited impact on soil pH at depth, possibly due to sampling errors and natural soil variability.

• Lime at 3t/ha increased pasture growth in the first year after application.
• Tune in for next year’s write up to see what effect the lime placement had at depth on soil pH.

• At Streaky Bay and Cungena in 2019, establishment was similar with dry sowing or sowing at the break, and at Minnipa establishment was better with dry sowing.
• There was a yield penalty if no fertiliser had been applied at Minnipa.
• Dry sowing increased grain yield at Minnipa by 0.2 t/ha compared to waiting for the break in the season.
• Dry sowing at Streaky Bay and Cungena reduced grain yield, by 0.7 and 0.3 t/ha respectively, compared to waiting for the break and sowing into a moist soil bed.
• All three sites showed a decrease in early dry matter with dry sowing.
• The herbicides and fungicides evaluated in the trial did not impact on plant establishment when dry sowing.

• Most legumes favour pHCa > 5.0 to a depth of at least 20 cm; acidic layers below 5 cm adversely affect root growth, nodulation, plant vigour and N2 fixation potential of acid-sensitive pulses.
• Ineffective incorporation of lime under minimum tillage systems confines the lime effect to the shallow surface layers (0-5 cm).
• An ‘acid throttle’ located between 5 to 20 cm in the soil profile is not detected using soil samples collected at standard depths of 0-10 cm and 10-20 cm, finer sampling at 5 cm intervals is recommended to detect acidic layers.
• Apply and incorporate adequate rates of fine grade, high quality lime at least 12 months before sowing acid-sensitive species to allow time for the lime to react and increase pH to the depth of incorporation.

• There was no effect of stubble retention on canola yield because it followed chickpea and there was very little, if any, stubble of chickpea.
• There was no significant effect of gypsum application on the yield of both canola and chickpea.

• The research aims to find rhizobia that will support lucerne growth on acidic soils.
• Good levels of nodulation found on acidic sand at Kingscote, despite soil acidity, pHCa 4.6
• Lucerne is highly recommended for KI soils that do not receive lengthy periods of water logging or have high levels of aluminum.
• Purchase freshly coated seed as background levels of lucerne rhizobia are low.

• With the current climate trending to decreased seasonal rainfall, each 1% increase in productivity is important.
• Increases in productivity can come from increased yield, more efficient application of inputs, or more timely grain marketing.
• Knowledge on the soil water holding properties, the time when the crop is taking up the most water from the soil and the current yield estimation models allows growers to market grain with more confidence pre harvest.
• Tools such as Yield Prophet, iPaddock Yield, soil moisture Probes and water use efficiency models are all very useful in assisting to predict grain yields with a relatively high level of confidence when accurately set up.
• In this project “iPaddock Yield” provided the greatest level of accuracy in predicting final grain yield on July 31st 2015. The simple French & Shultz “Broken Stick” model was very close to the accuracy of the ipaddock Yield at 77% & 74% accuracy.
• When there is confidence in the early to mid-season yield prediction combined with accurate soil Nitrogen testing and modeling, there is a greater chance of maximizing profits from applied nitrogen.

• The highest recorded water use efficiency (WUE) was observed at Spalding where 26.6 kg of wheat was produced per hectare for every mm of growing season rainfall.
• Growing season rainfall was below average meaning that stored summer soil moisture was very valuable in 2011.
• The WUE at Hart has been 14 kg/mm/ha or 70% calculated since 2001.

• The highest recorded water use efficiency (WUE) was observed at Spalding where 26.6 kg of wheat was produced per hectare for every mm of growing season rainfall.
• Growing season rainfall was below average meaning that stored summer soil moisture was very valuable in 2011.
• The WUE at Hart has been 14 kg/mm/ha or 70% calculated since 2001.

• The addition of a straw layer acted to reduce evaporation and significantly increased grain yields and water use efficiency in 2012, at 4 field sites.
• Soil evaporation also decreased with increasing light interception from larger crop canopies.

• The addition of a straw layer acted to reduce evaporation and significantly increased grain yields and water use efficiency in 2010 and 2011 at 3 field sites.
• Soil evaporation also decreased with increasing light interception from larger crop canopies.

The highest recorded WUE was observed at Spalding where 18.3 kg of wheat was produced per hectare for every mm of growing season rainfall.

• The best WUE for 2008 occured at the Tarlee site for barley, 28.5kg/mm/ha or 141%.
• Frost in August and October reduced WUE at Spalding.

• The best WUE for 2008 occured at the Tarlee site for barley, 28.5kg/mm/ha or 141%.
• Frost in August and October reduced WUE at Spalding.

• The best WUE for 2008 occured at the Tarlee site for barley, 28.5kg/mm/ha or 141%.
• Frost in August and October reduced WUE at Spalding.

• The best WUE for 2008 occured at the Tarlee site for barley, 28.5kg/mm/ha or 141%.
• Frost in August and October reduced WUE at Spalding.

WUE was generally low at the 4 sites in 2009, ranging from 9.1 kg wheat/mm/ha at Tarlee to 12.2 kg wheat/mm/ha at Spalding.

• This three year research project aims to increase the yield and reliability of field pea under water deficit and is a major pre-breeding target of Pulse Breeding Australia.
• Key traits being monitored include phenology, canopy and yield traits and the adaptive value of these traits will be explored.
• The trade-offs between adaptation to stress and yield in good environments will be investigated.
• Improving the reliability of yield of field pea in water limiting environments will help to provide a robust break crop option for growers in low rainfall regions.
• Preliminary results from the second season and summary of first season experiments are presented with more detailed trait data currently being analysed, with one more year to follow.
• Correlations between yield and canopy traits such as greenness and growth rate have been identified.
• We have also used APSIM to model the seasonal soil moisture stress for all environments.

A trial was established west of Moora in 2016 to investigate in season potassium response in barley. The main objective was to compare Lokomotive, a liquid potassium product, to the more commonly used granular muriate of potash (MoP).  Both soil and plant sample analysis showed the site to be marginal/deficient in potassium. Treatments were applied at GS 32. This timing was chosen as potassium deficiency is most commonly identified late in the growing season, when visual symptoms appear, and confidence in an economic response to applications of MoP in the current season is diminishing. At the time of application there were typical potassium leaf deficiency symptoms on the lower leaves. 

Good growing conditions were experienced in Moora in 2016 and resulted in high barley yields of 4.17 to 4.39 t/ha. There was a small yield response (1.7% to 5.3%) from both Lokomotive and MoP however this was not significantly different to the untreated control. The small response to potassium in 2016 may be attributed to the wet spring conditions that would have made potassium in the soil more available to the crop. Further evaluation of in season potassium application is required when spring conditions aren’t as favorable as 2016.  

 

 

• As a result of very poor seasonal conditions, there was no response to nitrogen applied to Yitpi wheat at either Rupanyup or Hopetoun in 2006, despite very low soil nitrogen levels.
• Delaying nitrogen application until after the end of tillering can allow a more accurate assessment of seasonal conditions to be made and money to be spent on nitrogen only if a response is likely.

• Electromagnetic (EM) zoning was strongly related to differences in pH at 10–30cm depth in two out of three paddocks.
• All three paddocks showed variability in chemical properties, with the EM zoning showing good separation of chemical properties between zones. This provides confidence that the zoning was suitable.
• Variability in plant growth needs to be examined ‘holistically’ rather than just focussing on one variable. While a paddock may show variation in plant available water (PAW), it may be that sodicity or subsoil acidity is the key limiter in plant performance, not water availability per se.
• Existing precision agriculture (PA) datasets, in conjunction with selected chemistry sampling, can be used to indicate relative change in PAW across paddocks, but not the actual volume of water storage.

• Yield differences between soil types were less than seen in previous seasons on this paddock.
• Yield responded to an extra 25kg/ha N at sowing on the deep yellow sand over gravel and shallow gravel yielded around 2.5t/ha.

• Yield differences between soil types were less than seen in previous seasons on this paddock, although they did yield in expected order.
• Starting nitrogen levels were quite high (>100kg N/ha) due to previous crop history.
• Overall with the better responses to applied N being achieved on the better soils or where there was plenty of starting soil nitrogen, this experiment has given encouragement to the idea of managing soil types (or management zones) differentially for N.

RESEARCH QUESTION

Can incorporation of lime economically remediate a subsoil acidity constraint on gravel soils?

RESEARCH OBJECTIVES

• To evaluate four rates of lime
• To compare three methods of incorporating lime
• To investigate an optimal combination of application rate and method of incorporation for ameliorating soil acidity

 

BACKGROUND SUMMARY

Forest gravel soils are common in the medium to high rainfall zone of Southern Western Australia and are estimated to account for about 2.4 million hectares of the state's farming area.  Non-wetting and soil acidity issues are known to constrain the productivity of these soil types, which are common throughout the Southern DIRT region. Considering this, limited local research has been conducted in regards to the effects of incorporating lime as a method to alleviate these soil constraints more effectively and economically than the traditional method of top-dressing.

The trial was collaboratively designed by Southern DIRT R&D committee members and staff, Wes Lefroy of Precision SoilTech, and the landholders, Roger and Simon House.  The focus of the treatments was to;

a)  Utilise the most economic source of lime for the landowners,

b)  apply the lime at a range of rates representative of both local practice and industry endorsed practice, and

c)  incorporate the lime with equipment which are known to improve the movement of lime through the soil profile compared to top-dressing; while having minimal complicating factors (i.e. poor seed placement) which are commonly associated with other forms of deep tillage.

The trial is located 12 km north of Kojonup and was chosen for its combination of targeted soil type (forest gravel) and pH range (4.5 – 4.8 CaCl2) up to a depth of 60cm.

 

 

The methods for incorporating lime in the trial are offset discs and one way plough, with knife-points at seeding included as a control.  Both offset discs and one way ploughs are generally used for the shallow incorporation of lime, and in this trial the depth achieved was approximately 10cm for the offset discs and 12cm for the one way plough. Research has shown that these incorporation methods can be more effective than the standard practice of top-dressing lime at increasing soil pH at depth by mixing lime into the soil profile when adequate rates are applied. While the lime is mixed well to the working depth of the implements, neither of these methods have the capacity to incorporate lime to depths beyond 20 cm.

Both offset discs and one way ploughs are considered by local growers as more cost-effective options for incorporating lime when compared to other methods (i.e. rotary spading). Annual plot soil testing and harvest yield will be the primary indicators used to assess how quickly and effectively the various treatments are able to raise pH at depth and increase production on forest gravel soils constrained by subsoil acidity.

Prior to seeding the trial in 2015, the site was extensively soil sampled to a 60 cm depth by Precision SoilTech.  An area with the capacity to accommodate the treatments with minimal variation in soil pH between plots was identified, however due to the nature of this site and the layout of the treatments (designed to be practical for the landowner to implement and maintain), there are inconsistencies within the trial which need to be carefully considered when assessing treatment effects. There were no systematic differences between the lime treatments in crop establishment and harvest yield, seemingly as a result of variability in soil pH and other characteristics between plots, complicated further by the layout of the trial, rather than a treatment effect.

It was observed that incorporation by both offset discs and one way plough did not reduced or cause uneven germination compared to knife-point at seeding, and during the season it was not visually evident that incorporation treatments had a major effect on crop growth and health compared to the control treatment.

While it may not be expected that shallow incorporation of lime would result in significant differences between lime treatments on a forest gravel soil type in the first year of a trial, it is imperative going forward into the next two seasons that a professional statistician helps analyse current and future data to ensure that subsequent interpretations can be improved, given the apparent impacts of site variability, and as treatment effects may become more pronounced.  It is expected that the ongoing plot soil testing conducted prior seeding each season will be the primary indicator used to determine whether incorporation of lime using either offset discs or one way plough can reduce soil acidity on a forest gravel at depth more quickly than the district practice of top-dressing, while yield responses will determine any economic benefits.

Mackellar wheat was cut at early‐mid stem elongation (GS32‐33), considered too late to be grazed without affecting grain yield, to determine effects under irrigation. Dry matter production was 22% higher compared with an earlier cut at GS30‐31 (start of elongation). With adequate soil moisture the late cut plots recovered well and grain yield was only 3% lower and not significantly different to the
earlier cut plots. Extended grazing of dual purpose wheat coupled with capacity to irrigate therefore provides increased economic and management flexibility.

These experiments provide a framework to allow growers in the Wimmera and Southern Mallee to use soil tests for nitrate N, organic carbon, and soil water to determine firstly, their yield potential, and secondly, whether there is a need for nitrogen fertiliser to achieve that potential.

• The trial was confounded by a severe shortage of plant available water (e.g. very low rainfall) and severe sub-soil acidity that resulted in toxic levels of plant aluminum concentrations that impacted negatively on crop productivity.
• The treatments (excluding prilled humate, which produced negative crop impacts) should be repeated (with VAM) at a site with more even sub-soil conditions. CALCIPRILL and VAM seed dressing showed particular potential for quality grain production and MAGPRILL showed particular potential as an effect agent for increasing soil pH.

• EM38 successfully mapped differences in soil water properties across the paddock.
• Positive response to fertiliser in wheat on wheat and higher yielding season.
• Barley yield decreased with increasing rates of nitrogen and phosphorus fertiliser.

• EM38 successfully mapped differences in soil water properties across the paddock.
• There were no significant yield increases from increased fertiliser.
• Reducing fertiliser on heavy soils had no negative impact on yield.

The main agronomic issues to be assessed in 2012 are:

• Targeting of seeding and post seeding nitrogen applications in line with identified changes in soil water characteristics ie changes in the ‘bucket’
• Assessment of gypsum applications over soil zones identified as having variations in sodicity levels. A trial has already been implemented which will allow economic assessment for several years.
• Sound agronomic and economic phosphorus fertiliser management in line with changes in productive capacity of soil zones and responsiveness of soil types to phosphorus applications.

• No yield differences were observed between the incorporated stubble and the standing stubble plots despite differences being recorded in plant growth during the year.
• The dry spring conditions had an impact on grain yields with no significant difference observed between treatments. 

• Yield differences were observed between the incorporated stubble and standing stubble plots.
• The hot dry conditions during November had a major impact on grain yield.
• Lodging was a problem in all of the plots with the incorporated plots particularly affected.
• At this stage no significat tincrease in soil orgainic carbon was observed.

The complex nature of these trials has generated a vast array of information. To best extract meaningful results it is necessary to pry apart the data to generate answers addressing the key facets of the hypothesis: see attached report for full details and discusison.

• Organic carbon accumulation in soil did not approach an upper limit.
• Increases in organic carbon accumulation were due to accumulated microbial detritus (i.e. dead microorganisms and microbial products).
• Soil with the lowest organic carbon concentration at the start of the experiment accumulated the greatest mass of stable organic carbon.
• Nutrients applied based on humus nutrient ratios promoted organic carbon stabilisation in soil.

• The Kerang site had a Potassium (K) soil level (0-10cm) that exceeded 600 ppm (Colwell K) at sowing and showed no yield response to additional K applied in crop.
• As was the case at Yenda the application of K as potassium sulphate at V4 or V8 saw no change in leaf tissue levels when compared to the control (no added K) assessed at V10 or tasselling.
• Harvest results showed no response to added potassium, indicating that the soil was able to supply the required potassium to the crop.
• There was no evidence of luxury uptake of K in tissue and grain samples (assessed in untreated, 40 (tissue only) and 80 kg /ha K).

• The Yenda site had a Potassium (K) soil level (0-10cm) that exceeded 500 ppm (Colwell K) at sowing and showed no yield response to additional K applied post sowing in crop.
• Application of K as potassium sulphate at V4 and or V8 saw no change in leaf tissue levels when compared to the control (no added K) when tissues were assessed at V8 or tasselling.
• Harvest results showed no response to added potassium, indicating that the soil was able to supply the required potassium to the crop.
• There was no evidence of luxury uptake of K in tissue and grain samples (assessed in untreated and 80 kg /ha K).

• Plant growth regulator (PGR) application at the recommended time of early stem elongation (Z31) did not alter root or shoot growth in the barley cultivar (cv) CompassA.
•  When PGRs were applied during early growth stages (Z12–13) root growth was inhibited or unchanged depending on the active ingredient applied and the application method.
•  When PGRs were applied early and when applied as a soil drench they inhibited root growth, but when applied at the recommended time for controlling stem height, PGRs had no effect on root
growth.

• However, the influence of seedbed N application (50kg/ha N) was evident in the crop structure scores, producing 150-200 more shoots/m2 and producing higher readings when the crop sensor Greenseeker® was passed over the trial than the GS30 stem elongation timing or the zero nitrogen controls.
• Despite a relatively low soil nitrogen reserve at sowing (43 kg/ha N 0-100cm), there was no influence of nitrogen on yield.
• In a trial subject to low levels of spot form of net blotch (SFNB), there was no response to fungicide over the untreated.

The work illustrated that in low fertility situations, which are more ideal for malting barley (2nd cereal low soil N reserves), there was no disadvantage to applying nitrogen applications at stem elongation (GS30-33).

• Pre-emergent herbicides can cause crop damage. Separation of the herbicide from crop seed is essential for crop safety, which is more easily achieved in knife-point & press wheel seeding systems but considerably more difficult with low soil disturbance single discs.
• Crop stubble can intercept & bind pre-emergent herbicides, which affects crop safety & herbicide efficacy. Low solubility herbicides such as trifluralin have a tendency to bind strongly to crop residues, which reduces the potential for crop damage but also limits its ability to provide effective weed control in situations with heavy stubble load.
• Choose the right herbicide for the job – not all pre-emergent herbicides behave the same so follow label recommendations closely.

Take Home Messages

Whilst the trial didn’t go according to plan there were still some key messages that arose:

• Maximising seed-soil contact is the aim at sowing especially for the larger seeds that require more moisture to imbibe and germinate compared to small seeds.

• Unseasonably low June rainfall hindered establishment of partially sown beans due to a drying topsoil. These may have been

OK under normal June rainfall conditions.

• Hair pinning can be a serious issue when using a disc seeder especially when sowing into wet/ moist lodged stubble.

• Solutions to avoid hair pinning – sow when stubble is dry (good in theory), keep stubble standing, use sharp discs and ensure bar

has sufficient down force to cut through tough stubble.

• Temperature did not influence extractable copper consistently.
• The effects of varied with the soil and on whether or not copper was added.
• When soils were incubated under a fluctuating temperature 20 to 40% less copper was extracted by EDTA then when incubation was constant at 20°.
• This result emphasises the need for caution in applying the results from constant temperature to field situations where the temperature fluctuates.

• Analysis of wheat crops sown after rice harvest in the Murray Irrigation Ltd districts (MIL) found that increasing yields required different management depending on soil type and irrigation layout.
• Four management factors that limit winter crop yields were identified: waterlogging, late season water stress, under-fertilisation and low soil pH.
• In the MIL districts alone, increasing wheat yields after rice from the current median to the 80th percentile would result in an additional 20,000–30,000 tonnes per annum ($4–6 million at $200/t).
• If all rice areas were sown to wheat after harvest every year and 80th percentile yields achieved, an additional 128,000–138,000 tonnes of wheat would be produced ($26–$28 million at $200/t).

• High-pressure injection shows promise as an alternative method for applying fertiliser into the soil.
• Deep banding fluid fertilisers with extra long knife points is another option which also showed promise.
• This research is still in its early days.

• Annual medic had lower levels of soil N (kg/ha) remaining in the soil post-harvest compared to balansa clover and subterranean clover at Sherwood.
• Annual ryegrass establishment was greater in crops following wheat, compared to crops following a pasture break crop.
• Overall pasture biomass production was greater at Bordertown compared to Sherwood.
• Wheat yields at Sherwood were greater following balansa clover and subterranean clover, compared to following canola and cereals options, wheat, barley and oats.
• Grain barleys Compass and Rosalind have demonstrated a capacity to produce biomass as a forage or hay option; feed tests need to be considered to ensure they are as favourable as forage options for livestock production. 

• Sow chickpea crops between standing wheat rows.
• Sow the following wheat crop directly over the row of the chickpea crop from the previous year.
• Keep wheat stubble intact and do not spread it across the soil surface.
• This will maximise yield of both chickpea and wheat crops and reduce the incidence of crown rot in the wheat phase of the rotation sequence.
   

• The use of Lucerne in the Upper Wimmera catchment and similar areas can be extended away from traditional areas such as river and creek flats.
• Introduction of lucerne into grazing systems lengthens the period of available green feed and can allow for enterprise change such as adding a lamb finishing operation to the farm business.
• Sowing time of lucerne is best suited to late winter.
• Soil testing is important to test for nutrient deficiencies and pH prior to lucerne establishment. Adequate lime and fertiliser should be applied to address deficiencies prior to establishment. Attention must be paid to ensuring that aluminium levels are suitable for lucerne production prior to sowing.
• A sub soil pH test should be taken to ensure that there are no acidity or aluminium toxicity issues at depth which could affect the lucerne plants as their roots penetrate the sub soil.
• Weed control is of critical importance before and during the establishment phase of lucerne pastures.
• Sowing depth of lucerne is important to allow an even germination. Care should be taken not to sow seed too deeply. The seed should be covered by 1 – 2 cm of soil, ensuring good soil contact.
• Control of annual grass and broadleaf weeds is of critical importance during the life of the lucerne stand if maximum production is to be achieved.
• A suitable fertiliser regime including the use of potash needs to be applied to replace nutrients removed by the lucerne system.
• Lucerne pastures can produce high quality hay which can enhance the farm’s production system if kept on farm.

• The negative effect of water repellence management at this site is at odds with other work in this project. In both years we have observed a lower grain yield in the banded wetter, mouldboard ploughing and spading treatments than in the control at this site.
• However, the average yield response to mouldboard ploughing and spading was 550 to 600 kg/ha over 28 sites.
• For further details please see the attached trial report.

• A factorial pot experiment involving four rates of soil-applied Mn (0, 0.75, 7.5 and 75 mg Mn/pot), four levels of CCN (0, 93, 186 and 372 second stage juveniles per pot) and 12 replicates of one Hordeum vulgare cv. 'Clipper' plant per pot was carried out.
• Four replicates were harvested 28, 73 and 192 days after sowing and each plant was assessed at harvest for growth, Mn content and level of CCN infection • Several plant growth parameters were measured non-destructively during growth.
• Resistance (ability of the pathogen to reproduce on the host) was not influenced by Mn nutrition of the host and equal numbers of nematodes invaded and developed to maturity on all plants despite Mn treatments resulting in plant Mn levels which ranged from severely deficient (0 Mn rate) and deficient (low Mn rate) to adequate (two highest Mn rates).
• However, tolerance (endurance of disease without severe losses in yield or quality) was considerably reduced by the combination of low Mn supply and higher levels of CCN.
• Plant height was reduced by increasing CCN numbers only at the two lowest Mn rates.
• These trends were typical of those observed in all plant growth parameters measured in the final two harvests including dry and fresh weight of roots and tops and total dry weight of grain produced per plant. Maturity was delayed in the severely affected plants.

Soil biota hold the key to sustainable crop production via impacts on processes like suppression of disease outbreaks and the cycling of essential nutrients.

1. In dryland conditions, planting in February increased yield of dryland mungbeans by 475 kg/ha over December planting.
2. Irrigation treatments increased mungbean yields by a maximum of 298 kg/ha and 653 kg/ha (planted in February and December respectively).
3. Application of water during mid pod-fill increased grain yield in the December planting but not the February planting.

The success of break crops to increase wheat production in the Eastern Wheatbelt is dependent on firstly addressing any physical and chemical soil constraints to crop production and where the previous land use is a chemical fallow. In this situation, the grain yield of lupin, chickpea, lentil and field pea was 0.97-1.42 t/ha 0.67-1.1 t/ha, 0.3-0.97 t/ha, and 1.2 t/ha respectively in a below average season. The yield of wheat following legume break crops tended to be higher than either canola or wheat planted in the remaining paddock area. The profitability of double break-crop sequences was negative in many of the sequences evaluated in this study compared to a positive profit for continuous wheat. The profitability of double break-crop sequences can be improved by the inclusion of high value legumes as the second break-crop, but further work is required to lower the risk of growing these species of crops.The yield of wheat following legume break crops tended to be higher than either canola or wheat planted in the remaining paddock area. The profitability of double break-crop sequences was negative in many of the sequences evaluated in this study compared to a positive profit for continuous wheat. The profitability of double break-crop sequences can be improved by the inclusion of high value legumes as the second break-crop, but further work is required to lower the risk of growing these species of crops.

• Hybrid choice and plant population had a significant impact on the yield of sorghum with irrigation. MR Buster yielded significantly higher than the other hybrids evaluated, while the higher population rates of 100,000 and 150,000 plants/ha yielded higher compared with the lower planting rates.
• The development and yield potential of the late season heads was compromised, and therefore the later developing sorghum did not take full advantage of the greater soil moisture of the intensive irrigation rate.

Conclusions

The experiment showed there are considerable productivity gains to be made by growers by selecting the right hybrid and plant population when irrigating sorghum. Irrigation management can significantly influence the growth of sorghum hybrids, affecting plant height, and grain development. Population did have an effect on yield during the trial with the higher planting populations of 100,000 & 150,000 plant/ha resulting in significantly higher yields than the 50,000 & 75,000 plants/ha. The higher plant numbers took advantage of the high plant available water from the irrigation treatments. 

On average, the surface retained treatments appeared to yield marginally better across this site. There appeared to be no difference in grain quality between treatments. There appeared to be no significant levels of insect pest or predator numbers in either the assessed standing stubble or the burnt treatment at the crop early emergence stage. There was however twice as many beneficial species in the stubble retained treatment. Insects that were present included both beneficial and harmful earwigs at very low levels, spiders and carabid beetles (that were of importance). Soil water data at crop anthesis indicates that the higher yielding treatments experienced lower soil moisture levels to 60cm, reflecting a possible increase in transpiration from greater crop biomass. Plant available water in the burnt and wider row treatments was higher, but not significantly different.

• Canola in rotation reduced Rhizoctonia inoculum levels and increased following cereal yields.
• Fluid fertiliser increased plant dry matter and yield on highly calcareous grey soils.
• A barley/vetch brown manure increased soil mineral nitrogen and this appears to have exacerbated Rhizoctonia disease symptoms on a following barley crop.
• Added carbon (10 t/ha/yr) has increased microbial respiration and microbial nitrogen.

• Differences in C input (dry matter production plus any additions) between the treatments were 24 t/ha at Minnipa, and 31 t/ha at
• Poochera over the last two seasons.
• Wheat at Minnipa produced between 0.5 t/ha of stubble in a poor season (2008) and 8.8 t/ha in a good season (2009).
• Doubling the seeding rate of wheat at Minnipa produced 1.4 t/ha extra stubble compared to the wheat control in 2009.
• Barley and vetch brown manures produced the lowest dry matter at both sites.

• The effectiveness of the Gamma sensor appears to depend on the geology of the area being surveyed.
• The Gamma sensor appeared to have very good correlations with clay % on the tertiary sediments, but further work is required on the Padthaway formation.

The main points to emerge from this farmer scale research are:

Depth: You can chase moisture to 3cm in good conditions but to achieve 25 plants/m2 you may need to increase your seeding rate.

Seeding Bars: There were large statistical differences in plant establishment between bars and between depths. The ability to achieve precise seed placement with different machines allows flexibility in adapting your seeding rate to the current seeding conditions if you know your seed size, germination percentage and establishment percentage achieved by your bar.

Although plant numbers ranged from 20 plants/m2 to 40 plants/m2, there was no statistical difference in yield, so you need to aim for 20-25 plants/m2 to increase your chances of successful establishment in marginal conditions.

• Corresponding to the biomass assessments, the compaction of the Trafficked zone had a notable effect on the crop performance.
• As a comparison of all sites there was an increase of grain yield of between 18 and 46% of the zero traffic area above the paddock assessments.

• Corresponding to the biomass assessments, the compaction of the Trafficked zone had a notable effect on the crop performance.
• As a comparison of all sites there was an increase of grain yield of between 18 and 46% of the zero traffic area above the paddock assessments.

• Corresponding to the biomass assessments, the compaction of the Trafficked zone had a notable effect on the crop performance.
• As a comparison of all sites there was an increase of grain yield of between 18 and 46% of the zero traffic area above the paddock assessments.

This trial sight was chosen as a typical regional soil type and had had a representative cropping rotation. Unfortunately the soil phosphorus levels (Colwell P) show that this site was possibly not phosphorus responsive as required for the purposes of this trial.
Adequate winter and late spring rains resulted in average grain yields. The trial was never moisture stressed and high grain protein levels indicate that the trial was not stressed for nitrogen. Visually it was difficult to pick any differences between treatments during the growing season.

• These data demonstrate a significant yield response to teh application of 20kg P/ha when compared to teh control. There were no yield differences to the various treatments. 
• The trial was moisture stressed in late spring but moderate grain protein levels indicate that the trial was not stressed for nitrogen. 
• Visually it was difficult to pick up any differences between treatments, however the poor growth control was very evident throughout the growing season and the Airseeder treatment appeared to lack early vigour, but at the end of the season this was not apparent. 
• The application of zinc as either foliar or as fertiliser at sowing (Granulock Supreme Z treatments) did not result in additional yield. 
• The liquid treatments did not prove to have any significant benefit over the solids fertilizer products; contradicting results from SFS Mininera trials in 2007 where liquid fertilisers proved to have distinct advantages as conpared to solids. 

• Early zinc uptake can be increased when zinc is applied as soil spray, seed coat or granular fertiliser but this does not necessarily increase yield.
• Products differ markedly in price per kg of elemental zinc so carefully consider your choice to get best value for money.
• Make sure choice of application method fits your farming system: for example if you are no-till then soil spray inefficient as not worked into root zone, foliar spray too late if you have zinc deficient soil as yield losses will already have occurred.
• Some products have short term benefits (seed coats and foliar sprays) and some longer term benefits.

There was no difference in wheat grain yield between the different phosphorus treatments in trial. The dry spring in 2007 resulted in considerably lower yields than expected due to a combination of severe frosts and moisture stress, delayed flowering and crop maturity. (There was substantial flowering “in the head” and failure of heads to fully grain fill.) There was also visual differences in growth across the trial (“patchiness”) that was evident in the high co-effeciency of variation (CV = 35.7).

Linseed is not new to Western Australia or the Great Southern region as it was grown in the Boyup Brook region from the 1940’s to the 1960’s. It was grown for fibre and milled at the Boyup Brook Flax Mill. Linseed (flax) Linum usitatissimum is a niche product and has the potential to offer an alternative revenue steam for producers outside of the traditional crop. Demand for Linseed has recently shifted to a health food. Linseed has several uses, it can be crushed for Linseed oil which is a rich source of linolic acid and Omega 3 fatty acid and the remaining linseed meal can then be used as livestock feed or it can also be eaten as a whole seed or ground.

Linseed also has agronomic benefits as a potential break crop that provides a disease break, the opportunity for alternative weed management strategies, provides an insect pest break and can be effective in reducing some soil borne root diseases and soil borne pathogens namely root lesion nematodes. Canadian research has demonstrated that cereal yields were higher when planted on linseed stubble compared to wheat stubble.

The aim of the project is to investigate agronomic packages which support the introduction and scale up of commercial cultivation of Linseed in the Great Southern region of Western Australia.

Consistent supply with volume is imperative to develop a market that has the ability to realise the full value of Linseed produced. Also, in order for growers to take up production it is important they have a full agronomic package available to grow the crop successfully. Finally, Linseed needs to generate an equivalent return per hectare of alternative rotational crops such as canola in order to expand into the rotation.

The key objectives of this project are:  

A: To determine if Linseed can be successfully grown under dryland farming conditions in the Great Southern region of Western Australia with the potential to scale up to commercial cultivation.

B: To determine if any investment is required into machinery and infrastructure by growers to grow linseed.

C: To develop basic agronomic guidelines to grow linseed in WA.

D: To assess the yield potential of two commercially available linseed varieties grown under dryland conditions in WA, Croxton and Bilton.

The project was conducted over two years in 2019 and 2020. In 2019 the trials were conducted in small plots across three sites. In 2020 the trials were conducted as producer demonstration sites utilising grower machinery and large-scale plots.

In 2019 three sites were located across the Great Southern Region of Western Australia covering a variety of soil types, climates, paddock histories and growing conditions. The trials sites were in the shires of Darkan, Wagin and Kojonup. The trials involved growing two commercially available varieties Croxton and Glenelg over three times of sowing (TOS) 10 to 14 days apart at three seeding rates (SR): 35, 40 and 45 kg/ha and applying three top dressed nitrogen application rates (low, optimal and high) 40, 80 and 120 units N/ha.

Over the three trial sites, the seeding rates and nitrogen application rates trialed did not consistently result in significant differences in grain yield or oil quantity and quality. Time of sowing had the greatest impact, with the earliest time of sowing generally resulting in higher grain yields. Glenelg on average had a higher grain yield and oil quantity, with Croxton having the highest oil quality.

Trial Site

Average Site Yield

t/ha

Darkan

0.562

Wagin

0.914

Kojonup

0.998

Table 1: Average Site Yields in 2019 (Below average rainfall)

The Darkan site plant counts were the highest, however this was not reflected in the yield. Darkan was the lowest yielding of the three sites. This may be due to the below average rainfall and lack of finishing rains experienced on the non-wetting forest gravel soils at this trial site. Kojonup and Wagin on average achieved nearly double the yield of the Darkan site despite lower plant counts and early plant disease.

In 2020 four demonstration/bulk up sites were established across the Great Southern Region covering a range of soil types, rainfall, rotations and growing conditions. The four sites were located in Katanning, Wagin, Darkan and Kojonup.

The methodology in the second year of the project was to bulk up the Linseed seed for future commercial production and to also integrate high level variety comparisons between the two varieties being utilized in the project Bilton and Croxton. Two sites, Wagin and Darkan, incorporated replicated plot treatments as a variety trial with the other 2 sites being predominantly bulk up sites.

The key outcome of any variety demonstration is the final yield result. Due to operational difficulties within the demonstration some yield data is not available however the key findings from the data available was:

• Bilton yielded on average 0.95 MT/Ha and 85% of Canola
• Croxton yielded on average 0.86 MT/Ha and 72% of Canola.
• Bilton out yielded Croxton on both sites.

The seasonal conditions may have contributed to Bilton out yielding Croxton. Bilton is a slightly shorter maturing variety and the below average rainfall received in 2020 is expected to have favoured shorter season varieties.

The project has successfully set in the place the ability for growers in the Great Southern region to scale up production of Linseed and demonstrated its ability to fit within the current rotations with the additional benefit of assisting in the long-term management of soil borne root pathogens.

However, for the scale up of the commercial cultivation of Linseed there is the requirement for beyond farm gate systems to be in place before producers will scale up production. An active market to determine a fair price, storage and handling facilities off farm to enable harvested grain to be stored before delivery to consumers, supply chains in place which enable efficient delivery of the grain anywhere around the world and long-term buyers/processors who will receive the grain year in year out. There is still a lot of process to be put in place before Linseed production will scale up to a considerable level.          

Grower adoption beyond the project has continued with over 60 Ha planted in southern WA in 2021 across 4 growers. Confidence in the supply chain beyond the farm gate remains as the major obstacle stopping increased uptake and requires addressing before increased production can be expected.

• Chelated iron applied to the soil before sowing increased active iron in leaves by 42% and dry matter by up to 46% early in the season.
• The 9% increase in grain yield following iron application to soil was not significant.
• Foliar iron had no significant on activeFe, leaf colour or photosynthesis.
• Lime induced iron chlorosis was suspected.

Population had no effect on yield. Populations as low as 130 plants/m2 had similar yields to that of 180 plants/m2.

Plant establishment varies greatly with conditions post sowing. The long term average for cereals at the ICC Trial Block is 70%, but colder soil temperatures and soil moisture can see establishment fall to 50%.

Drainage is the key to successful irrigated pulses. The subsurface drip irrigation without beds resulted in prolonged soil waterlogging which impacted establishment and plant survival in spring.

• Site experienced extended dry conditions after seeding due to late follow up rain.
• SACOA will continue local soil surfactant research and evaluations in 2004.