• Legume crops consistently increased pre-sowing soil nitrogen in the year following the break.
• Two-year break phases that included a brown manure vetch phase have generally resulted in the highest pre sowing soil nitrogen levels in the subsequent wheat crops.
• One and two-year break phases reduce Rhizoctonia soil inoculum, however levels increase significantly following the first cereal crop.
• Two-year break treatments generally reduced brome grass populations in the cereal phase, however all rotations relied on Clearfield herbicides for brome grass control by the second wheat crop following the break.
• The benefits from extra soil water following some break phases in this trial have been variable and small.

When sub-soil water is present, growing high value canola and legume break crops can be profitable in the Mallee.

Where brome grass seed bank populations are high, break crop sequences of longer than two years are necessary to decrease numbers, and keep them down.

The application of CLF herbicide chemistry is effective in reducing brome grass populations, but herbicide resistance will develop quickly if they are used repeatedly in the same paddock.

• The choice of legume species and management were found to influence the amount of nitrogen fixed by both crop and pasture legumes byaffecting either legume reliance upon N2 fixation for growth or changes in dry matter accumulation.
• Medium to high soil mineral N concentrations at sowing appeared to suppress N2 fixation by field pea more than lupins or faba beans.
• Pulse legumes grown for grain generally result in lower net inputs of fixed N.
• Available soil N following either legume crops or pastures can represent an additional 40 to 90kg N/ha in the 1st year.
• The increased N uptake by the 1st wheat crop grown after legumes was equivalent to 27-40% of N in the previous year's legum residues.

• Wheat sown after break crops produced up to 1 t/ha more than wheat after wheat
• The greatest benefit of the break crop was produced at the earliest sowing
• Safflower produced the break crop effect but produced low wheat yields, small grain but high protein due to drying out the soil profile.

• The single cropping phase of cotton achieved the highest returns for both $/ha and $/ML.
• The double cropping treatment of canola and maize achieved the highest returns for $/ha.
• All double cropping treatments achieved similar returns for $/ML.

More reliable management strategies for the production of broad leaved phases.

Identification of more reliable break phase options.

Guidelines to identify trigger points for when, for how long and which break phases to use for improved farming systems outcomes.

Reliable estimation of risks with break phases as well as their total impacts on following cereal crops.

• Break crops can be just as profitable as wheat crops.
• Antas sub-clover (for hay production) as the break crop was the most profitable option.
• Beans were the most effective at fixing nitrogen, averaging 13 kgN/tDM produced.

• Break crops can be just as profitable as wheat crops
• Antas sub-clover (for hay production) as the break crop was the most profitable option
• Beans were the most effective at fixing nitrogen, averaging 13 kgN/tDM produced

• Time of Sowing; get it right after the break crop.
• Effects of the break crops are often realised for at least 2 seasons after being planted.
• Beans consistently fixed the most nitrogen over the 3 year period; averaging 15Kg N/ha per tonne of dry matter produced (above the ground).
• Financial benefit of a break crop needs to be worked out over life of rotation.

There were no clear significant detrimental effects found of the herbicides on any of the wheat varieties tested. However, Barunga and Beulah yielded significantly better than Meering and Ouyen.

• Glyphosate at either 1.0 or 1.5L/ha applied at the flowering stage of ryegrass was very effective in reducing the viability of seed set.
• Herbicides applied to barley at the soft or firm dough stage of grain fill did not reduce individual grain weight, grain viability or early plant vigour.

• Glyphosate and glufosinate applied to flowering annual ryegrass give better control compared to later applications. While paraquat and diquat can be applied later.
• Paraquat 0.8L/ha or glyphosate 2.0L/ha applied to flowering ryegrass gave over 90% control of viable seed set per head.
• Glyphosate at 1.0L/ha or glufosinate above 2.0L/ha gave more than 65% control of ryegrass seed heads.
• Herbicides applied to barley at the soft or firm dough stage of grain fill did not reduce grain number, weight or viability.

• All herbicide treatments reduced grain yield by 13% in TOS 1 and at least 8% in TOS 2.
• Glyphosate (540 g/L) at 3.0L/ha was the only treatment to significantly reduce germination, down to 7% at TOS 1 and 88% at TOS 2.
• For each application timing glyphosate (540 g/L), glufosinate (200g/L) and paraquat (250g/L) significantly reduced the germination percentage of ryegrass.

• Crop topping provides an excellent strategy to control escapee or resistant weeds in field pea
  crops.
• Yield can be severely penalised if crop topping occurs too early.
• Correct variety choice and careful timing of crop topping is essential
• Varieties should be selected to achieve maximum yield simultaneously with maximum weed
  control.
• Ontime spraying achieved excellent weed control as annual ryegrass and wild oats were at
  the flowering stage.

• Crop topping at the recommended time of application (ryegrass milky dough) resulted in no yield loss for any genotype.

• Results generally showed that earlier maturing lines displayed less yield loss in
  crop-topping treatments than later maturing types.

• No significant response to crop topping treatments was observed.

• No significant response to crop topping treatments was observed.

• No significant response to crop topping treatments was observed.

• Due to extreme weather events during harvest it is difficult to determine any significant trends from this data. This trial will be repeated in 2011.

• The new blue lines showed yield 30% to 75% higher than Excell, with some lines having better or similar quality characteristics to Excell.

• The new blue line OZB1309 displayed yields equivalent to PBA Pearl, which is generally the highest yielding pea in many NVT and breeding trials in Victoria.

• Crop-topping wheat with glyphosate can result in yield loss and grain size reduction if done too early.
• Later crop-topping timings can produce grain quality and yield similar to untreated grain.

• The dry and hot November in 2009 led to early senescence of pulse varieties and reduced
  grain yields in later maturing varieties. Many responses to the crop-topping treatments may
  have been masked by this rapid senescence eg Almaz and GenesisTM114 chickpeas.
• Some surprising results were observed in 2009, which may be due to either genetic
  responses or responses to rapid finish to the season eg forage pea grain weights.
• Field peas and Faba beans generally showed no yield loss at the recommended timing for
  crop-topping of ryegrass in 2009. Lentils and chickpeas showed significantly higher yield
  losses from crop-topping, averaging 15 and 21% yield losses respectively at this timing.
• The large biomass, mid-late maturing lentil Boomer also showed a yield loss when croptopped later than recommended for ryegrass control. These results indicate poor suitability of some lines to this agronomic practice.
• Early maturing lentil and chickpea lines showed yield losses from this practice at the
  recommended timing. This demonstrates the difficulty in employing this weed control
  technique in these crop types.
• The early crop topping treatment reduced grain yields of most pulse varieties. Field peas
  OZP0602 and Yarrum at Turretfield, and the Faba bean AFO3001 showed no difference in
  grain yield at the early cop-top timing and the nil, indicating good suitability to this practice.

• Dry and hot spring conditions reduced grain yields and led to early senescence of pulse
  varieties in 2008 particularly in late flowering and/or maturing types. Many of the grain
  yield reductions expected at the mid and late crop topping timings were ‘masked’ due to
  premature senescence in many varieties brought on by these dry spring conditions.
• The early crop topping treatment reduced grain yields of field peas, lentils and chickpeas
  compared with the nil treatment, however there were field pea and lentil lines identified
  which did not incur a yield loss at this timing, indicating suitability to this agronomic
  practice.
• Some lines in all crops were found to incur yield loss and grain weight reductions at the
  appropriate timing for crop topping indicating poor suitability to this agronomic practice.
  jb66 Page 75 30/04/2009
• Not all early flowering and maturing lines were able to be safely crop topped in the 2008
  experiments nor did all late lines always incur a yield loss. Further evaluation is required to
  confirm findings in a year where varieties are not prematurely senesced by drought
  conditions.
• Detailed grain quality measurements (seed size distribution, colour, hydration percentage)
  are currently occurring on some treatments and varieties to assess the effects of crop topping and desiccation on seed quality.

• Early maturing desi chickpea varieties incurred the least yield loss at the recommended timing for crop-topping. Later varieties and kabuli types showed significant yield loss at the recommended timing and three later kabuli varieties showed yield loss at the late timing.

• Similarly to previous (2013) trials, there was no interaction between crop-top timing and variety. This means that the varieties evaluated in these trials had the same grain yield response at the different crop-top timings; therefore no variety was better suited to crop-topping than another. This finding has been consistent in faba beans over time but different to all other crops (lentil, field pea, chickpea).

• The wet season end in 2010 meant that all varieties showed reduced yield and grain weight
  from the early crop-top timing, regardless of maturity.
• At the recommended crop-top timing yield of the later maturing lines Parafield, Yarrum and
  Glenroy was significantly affected, while some later maturing lines were not. This may have been a result of a moderate powdery mildew infection at this site, which sped up maturity of
  sensitive lines. Yarrum, which has mid maturity and is powdery mildew resistant, would not
  otherwise have been expected to show this yield penalty at this timing as shown by 2009
  results.
•  Further work is required to validate these results.

• Yield losses from Early crop-topping generally followed cultivar maturity, with latest maturities
  showing highest losses. Parafield and Alma were the only varieties to show yield loss at the
  Recommended timing, supporting previous findings that these later maturing varieties are not as well suited to crop-topping as recent releases PBA Twilight, PBA Gunyah and PBA Oura. Kaspa and Yarrum continue to show a variable result across seasons at this timing.

• The wet season finish in 2010 favoured chickpea production, however this made timely
  weed control through crop-topping very destructive.
• There was little varietal response from crop-topping in 2010.
• All varieties showed reduced yield when crop-topped at or before the recommended timing
  for optimum ryegrass control (milky dough stage).
• Crop-topping 2 weeks after the recommended timing was the only timing considered “safe”
  for chickpeas in 2010, with only one variety showing reduced grain yield and one variety
  having reduced grain weight.
• These results emphasise the difficulty in employing this weed control method in chickpea.

• The wet and late finish to the 2010 season meant that early crop-topping was very detrimental to yield of all lentil varieties
• Later maturing lentil varieties also showed a yield penalty from crop-topping at the recommended timing (ryegrass milky dough stage).
• CIPAL0501 was the most sensitive variety to crop-topping, showing a reduction in yield from crop-topping at all three timings. This variety also has the latest maturity in this trial.
• The early crop topping treatment reduced grain yields of most pulse varieties, while the late
  crop-top timing had no effect on grain weight.

• There was limited varietal response from crop-topping in 2011. This may be due to below  average rainfall during late October and early November, the rapid finish on a shallow soil and the relatively late sowing date, suppressing some yield potential of untreated plots.

• Chickpea are generally considered to be unsuited to crop-topping due to their high yield losses, and are the least suited of the four pulse crops commonly grown in South Australia.

This trial was drought stressed, however, barley and canola do look attractive with the right choice of variety in a more typical season.

• The no-till sowing system had significantly higher grain yields at Hart in 2011.
• Higher fertiliser nutrition significantly increased protein, but not grain yield.
• The strategic treatment produced the most dry matter and shoot nitrogen.
• Mice damage significantly reduced crop emergence in the disc treatment.

• There was no significant difference between sowing systems or level of nutrition on grain yield but higher grain yield at the higher nitrogen rate.
• Levels of brome grass were higher under the early sowing no-till plots and annual ryegrass was lower in the disc system.

• There was no significant difference between sowing systems or level of nutrition on grain yield.
• Levels of brome grass were higher under the early sowing no-till plots and annual ryegrass was lower in the disc system.
• There is very little difference in long term gross margin between seeding system or level of nutrition.

• The disc and the early sown no-till tillage systems produced the highest grain yields, 1.41t/ha and 1.36t/ha respectively.
• The early sown no-till system had the lowest protein and the highest screenings.
• The disc tillage treatment had the least available soil nitrogen in autumn.

• All the legumes sown - peas, lupins, sub clover and faba beans - were equal in terms of their nitrogen-fixing capabilities, reflecting the importance of having well nodulated legumes.
• The average amount of N fixed by the legumes was calculated at approx. 86kg/ha.
• In year 2, this residual N gave rise to a approx. 1 t/ha canola yield advantage.
• In yera 3, no differences in residual nitrogen from legumes were measured.
• Linseed extracted more moisture, from a greater depth, than the faba beans in the same year and all subsequent crops - canola and oats.
• The linseed was able to dry the soil profile in a decile 10 year (812mm rainfall). This is a potential solution for farmers wanting to dry out their soil profile.
• Two years after growing linseed, soil moisture levels were even.

• Dry and hot spring conditions led to poor pod set and early senescence of faba bean varieties in 2007. Grain yields of earlier maturing varieties were higher than those of later maturing types.
• There was no significant interaction between crop topping timing treatment and variety
  performance for grain yield as late varieties were lower yielding in all treatments, including
  the nil treatment due to the dry seasonal conditions.
• Generally earlier maturing varieties incurred lower levels of grain yield loss than later
  maturing varieties when crop topped at the appropriate stage for effective ryegrass control.
  However this difference was not significant in the 2007 trial.
• The concept trial methodology for evaluating relative yield loss due to various crop timings
  was found to be sound and will be repeated in 2008, although trial layout changes will be
  made to improve spraying logistics. A very early timing treatment will be added to assess
  the extremes of yield loss potential in all varieties and detailed flowering and maturity
  scores will be taken. Field pea, lentil and chickpea varieties will also be evaluated.

• Durum breeders’ lines screened in 2008 and 2009 do not show consistently improved resistance or tolerance to crown rot.
• Hyperno performed somewhat better than Kalka or Tamaroi.
• Data from at least two seasons is needed to make sound decisions about the response of entries to crown rot.

• Some new durum lines show promise of improved resistance to crown rot.
• Yield loss in Hindmarsh in this trial is a reminder that barley can also exhibit yield loss from crown rot.
• Percentage yield loss from crown rot may only be small in a good season, but this can equate to significant production loss.
• Knowing the risk of yield loss from crown rot in paddocks prior to sowing is an important management strategy.

• Growing conditions in 2016 were very wet and mild, with rainfall from May to September one of the wettest on record. Growing season rainfall was well above average with 491mm recorded at the site.
• The conditions in 2016 did not favour the expression of crown rot, with only minimal disease observed. As a result there were no significant interactions between any of the seed treatments in this trial.
• Durum wheat is more susceptible to crown rot than barley. The durum wheat variety Aurora was used in this trial and was out-performed by the barley variety LaTrobe, yielding significantly lower.
• At tillering, the NDVI of treatments not infected by crown rot were significantly higher than those infected by crown rot. At flowering there was no significant difference in NDVI between any treatment

• Durum breeders’ lines Td17/1 and WID902 showed promise of improved resistance/tolerance to crown rot.
• Hyperno and AGT Katana performed best of the recently released durum wheat and bread wheat cultivars, respectively.
• Gladius expressed significant crown rot symptoms (but not whiteheads) and may contribute to rapid build up of crown rot inoculum.

• Durum breeders’ lines Td17/1 and WID902 showed promise of improved resistance/tolerance to crown rot.
• Hyperno and AGT Katana performed best of the recently released durum wheat and bread wheat cultivars, respectively.
• Gladius expressed significant crown rot symptoms (but not whiteheads) and may contribute to rapid build up of crown rot inoculum.

• Durum breeders’ lines Td17/1 and WID902 showed promise of improved resistance/tolerance to crown rot.
• Hyperno and AGT Katana performed best of the recently released durum wheat and bread wheat cultivars, respectively.
• Gladius expressed significant crown rot symptoms (but not whiteheads) and may contribute to rapid build up of crown rot inoculum.

• Durum breeders’ lines Td17/1 and WID902 showed promise of improved resistance/tolerance to crown rot.
• Hyperno and AGT Katana performed best of the recently released durum wheat and bread wheat cultivars, respectively.
• Gladius expressed significant crown rot symptoms (but not whiteheads) and may contribute to rapid build up of crown rot inoculum.

• Durum breeders’ lines Td17/1 and WID902 showed promise of improved resistance/tolerance to crown rot.
• Hyperno and AGT Katana performed best of the recently released durum wheat and bread wheat cultivars, respectively.
• Gladius expressed significant crown rot symptoms (but not whiteheads) and may contribute to rapid build up of crown rot inoculum.

• Yield losses of up to 20% due to crown rot were observed in 2015.
• Losses ranged from 2%–11% in bread wheat and 1.5%–3% for barley.
• Crown rot has a significant effect on gross margins when comparing grain quality and yields between crown rot treated and untreated plots.
• Select the highest yielding varieties rather than those with enhanced crown rot tolerance to minimise losses.
• Reduce the risk of crown rot infection by using crop rotation as well as stubble management.

• Yield loss response curves are an additional tool to help growers in varietal selection decisions to maximise returns where disease is present.
• Variations occurred in the yield response of varieties to crown rot, along with their resistance to this disease.
• The variety Suntop, although displaying crown rot symptoms similar to that of a susceptible variety, demonstrated a greater ability to maintain yield where disease was present than other varieties that are considered tolerant.
• The selection of varieties based purely on current resistance categories may be overlooking genetics with improved tolerance, such as the variety Suntop.
   

Based on this trial it appears CG could be used as a substitute for DAP fertiliser in cereal production however blending with urea to ensure adequate N would be essential. 

• In the first year of trials (2012) a 75 kg/ha rate of Crystal Green significantly increased lentil yield by 18% compared to the nil (100%) and DAP treatments.
• In the second year of trials no carry-over effect of Crystal Green or DAP was observed on wheat grain yield.

There are some new lines that are worthy of consideration by growers in the high rainfall zone of southern Australia. Tribute, a New Zealand variety topped the trials, however there are 2 new CSIRO lines which will be in limited supply this year, namely 95102.1 and H123.1 which performed very well.

Visually the germination in the control (not crushed) was significantly less than the crushed area, given the ability for the airseeder to create a seed bed and bury the seed. The return on investment from the rock crushing treatment applied shows that it would require approximately 3 years to provide a return on investment for this trial.

• Ryegrass numbers were lowest in a minimum tillage and direct drill situation.
• Pre-sowing herbicide application with trifluralin and Avadex type products all reduced ryegrass number compared to the control, however, none of the treatment were commercially acceptable.
• Herbicide options based on trifluralin or Avadex are an additional tool in the battle with resistance ryegrass.

Effective control of summer weeds before cropping can increase both grain yield and quality. The key to increased yield potential lies in additional sub-soil moisture available to the crop during the subsequent growing season. Summer weeds also deplete mineralised N reserves. Provided there are no limitations preventing crop roots from accessing the subsoil, the additional soil moisture can be seen in higher grain yields and generally grain protein and test weight.

• There was no statistically significatn difference between the control and the CFF treated plots.
• The dry conditions experienced in 2007 impacted on this demonstration which indicated a need for further reserach into the effectiveness of this product in a more favourable season.

There are no significant differences in yields between the control and the CFF plots on a wodjil soil type.

It is our plans to work with each of the system leaders and refine their programs to improve the performance of their systems.
 

• Have established at what level the bucket is full
• Have a better understanding of where it becomes empty
• Have increased our confidence in utilising these tools
• In-crop nitrogen sampling has been a vital tool in assessing the effectiveness of the modelling

Key findings:

• Nitrogen (N) decision making requires a good understanding of background soil and plant science, and soil test interpretation.
• Training for new agronomists needs to be a priority issue.
• Senior NSW agronomists identified crop yield expectation as guided by soil moisture at sowing (or at the time of N decision making) as the most important determinant of N fertiliser requirement.
• Further research is needed to increase the understanding of how management practices affect potentially large gaseous N losses. 
• Changing from legume pasture-crop sequences to continuous cropping in many central and southern areas of New South Wales is posing new questions for managing N supply. The absence of N-fixation by pasture legumes is seen as a substantial loss of N-buffering capacity.
• Despite most advisers choosing soil testing as a key approach for determining N fertiliser required, many of their clients had a lower confidence in soil testing, citing ‘high perceived variability in soil nitrate results in the lead up to sowing’.
• Conclusions and Recommendations Senior advisers highlighted the importance of quality training in N decision-making, understanding the background soil and plant science involved, and soil test interpretation for the next generation of agronomists, with training courses including representation from highly experienced local agronomists.
• The understanding of gaseous N losses requires further research, development and extension to the grains industry. Recent field research in the north was limited in scope and produced challenging outcomes that can potentially lead to large practice changes in when and how N fertiliser is applied. Further research and development work is warranted to answer more of the practical questions growers and advisers are asking in regards to losses associated with various alternative practices.

• The northern results on N loss pathways are less relevant to advisers in the central and southern regions where N application timing, soil type and climatic differences are generally quite different from the dominant medium-heavy clays of the north. New N loss research is recommended for the lighter textured soils in regards to the potential for N volatilization losses from surface N application of various products. Economic outcomes from the various strategies being practiced are also needed. Nitrogen loss research should focus less on expensive slow-release products and more on optimising results from urea, the cheapest N source.

• Research into better soil water measurement was seen as a priority area, especially given the importance all advisers place on knowing this when making expensive N-fertiliser decisions for a coming cropping season. Zonal management within paddocks is not possible with single site characterisations, so atypical areas of paddocks are over or under-fertilised.

• The very early application of N fertiliser ahead of a winter cropping season is well established, but what is not known is how well the subsoil N may be protected or at risk from denitrification in flooding events. Also, better knowledge on specific N use within the profile during the cropping season will help growers to know when late-applied N is likely to be inaccessible to crop use.

• Nitrogen mineralisation was highlighted by agronomists from all three regions as an area for greater understanding with regards to the differences caused by climatic conditions, especially rainfall. They also require better understanding of the N produced from both native organic matter and recent legume pasture residues.

• There are a number of good decision support tools available currently, with several advisers suggesting that combining the best points of each into one package, even one available as an app, would be highly useful, particularly one with good grower-friendly reports.

• Many farmers have low confidence in soil testing.  This may be related to a range of factors from poor sampling strategies, to poor sample handling, to poor service from laboratory analysts, to insufficient sample numbers or poor interpretation of the results. It is seen as an expensive option for many, with some advisers looking for quicker and cheaper means of estimating soil mineral N.

• Variety-specific N management packages were seen by some senior advisers as key areas for continued research funding, as results from some new varieties have been quite different in terms of N uptake and protein outcomes.

• Making nitrogen (N) management decisions requires an understanding of soil and plant science, and soil test interpretation.
• Training new agronomists is a priority.
• Senior NSW agronomists identified crop yield expectation as guided by soil moisture at sowing (or at the time of N decision making) as the most important determinant of N fertiliser requirement.
• Further research will increase the understanding of how management practices affect potentially large gaseous N losses.
• Changing from legume pasture-crop sequences to continuous cropping in many central and southern areas of New South Wales is posing new questions for managing N supply. Less frequent pasture legume phases with their N-fixation benefits to the soil is seen as a substantial loss of N-buffering capacity.
• Despite most advisers choosing soil testing as a key approach for determining N fertiliser required, many of their clients had a lower confidence in soil testing, citing ‘high perceived variability in soil nitrate results in the lead up to sowing’.

• Deep phosphorus (P) placement at a depth of 20 cm resulted in root proliferation in desi chickpeas at Terry Hie Hie.
• Deep P applied in the plant line produced more vegetative biomass compared with deep P placed between alternate plant lines (66 cm spacing) four weeks after sowing.

 

• 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.

• The trial area was seeded in June 2015 to wheat by Peter Negus, while he was seeding the surrounding paddock.  Unfortunately, the seeder ran out of seed as the trial was being sown.  The result was that there were large unseeded strips running through the trial. 
• Rainfall at the site was very poor in September and October 2015; approximately 70% below average for that period.  As a result, cereal crops on soils with low water holding capacity were badly affected, with yields well below average.
• Analysis of the harvest results (excluding plots affected at seeding) showed no significant differences, leading us to conclude that either (a) the tillage and lime treatment effects have ‘worn out’ at the site, or that (b) poor rainfall in September and October severely reduced yields, obscuring any other effects.  We believe that (b) is more likely.
• This trial will be sown to lupins in 2016.

The pH results from this trial show some interesting trends. 

The treatments with greater disturbance at depth (spade, deep rip + spade, mouldboard) tend to decrease surface pH.  This is of concern if the ‘new’ topsoil pH is acidic enough to inhibit root development. 

The treatments with greater disturbance at depth (spade, deep rip + spade, mouldboard) tend to increase midsoil pH most rapidly.  This is the effect hoped for.  The differences between treatments are generally not significant, but more intensive sampling may tease out differences.

The treatments with greater disturbance at depth (spade, deep rip + spade, mouldboard) tend to increase subsoil pH most rapidly.  This is the effect hoped for.  The differences between treatments are generally not significant, but more intensive sampling may tease out differences.

• In year one of this trial, there was no yield differences observed with the application of chicken manure, artificial nutrients or no nutrients
• Cultivation with the mouldboard plough resulted in better yields compared to no cultivation or deep ripping in the first year regardless of nutrients
• Grain protein was significantly higher in the chicken manure treatments
• Large amounts of dry matter was produced under the manured treatments however it didn’t make any difference to yield

• Deep placed lime can improve yields on acidic soils in a very dry season but significatn yield increases were only achieved when lime was place directly into the subsoil to depths of 31 or 51cm.
• Generally, responses from deep placed lime have been recorded in either the year of application or 1-2 years after application.

• Investigated infertile soils over clay in SA and Victoria.
• Earlier work showed that a "shotgun" mix of N, P, zinc, copper and manganese placed at 40cm regularly doubled cereal yields.
• Have shown that such applications have onging residual benefits.
• Need at least 25cm of sand or haying off can occur in dry years.
• Deep ripping tyne type and spacing appear to be less important than depth of application at 40cm.
• Apply nutrients at a rate which would double current yields.
• Management of erosion after ripping is the primary challenge.
• Addition of deep nutrient during ripping would appear to be a good option with reliable benefits.

• Removal of soil compaction and subsurface acidity via deep banding lime to 30cm resulted in 18% yield increase over the untreated control.
• Despite the gross margin of the deep banded lime treatment being $35/ha less than the control in 2005, the benefits of deep ripping and lime application will still be realised in future years.

• Removal of soil compaction via deep ripping to 30cm resulted in  44% yield increase which equated to a gross margin of $38/ha more than the untreated control
• Addition of lime did not significantly improve yield in 2006, however, it is possible that a response will be gained in future years as subsurface acidity is present in the soil profile.

• Removal of soil compaction via deep ripping to 30cm resulted in  44% yield increase which equated to a gross margin of $38/ha more than the untreated control
• Addition of lime did not significantly improve yield in 2006, however, it is possible that a response will be gained in future years as subsurface acidity is present in the soil profile.

• Removal of soil compaction via deep ripping to 30cm resulted in  44% yield increase which equated to a gross margin of $38/ha more than the untreated control
• Addition of lime did not significantly improve yield in 2006, however, it is possible that a response will be gained in future years as subsurface acidity is present in the soil profile.

This work has demonstrated that it is possible to incorporate lime into seams in the soil profiel which can increase the soil pH and decrease the levels of toxic aluminium.

Deep cultivation strips on growers’ properties did not show much in the way of early responses and so did not excite much grower interest as a direct diagnostic of the hardpan conditions in their paddocks. However, at responsive sites, there was a lot of grower interest to the level where it might be worth funding another year of this direct diagnostic approach in the hope that early season conditions are conducive to major nitrogen growth responses.

• Yield increases from deep ripping ranged from 220 to 750 kg/ha.
• Deep ripping demonstrations provide a tool to assess possible yield gains across various soil types.
• Replicated trials are needed to validate the yield increases seen at this demonstration site.

• Deep ripping dry sand was more effective with two passes (or shallow leading tines); less cloddy.
• Yield benefits of 410 kg/ha (18%) from deep ripping were mainly due to better head fill. Better head fill was probably due to better cooling of the crop in hot weather due to better supply of moisture.
• Extra moisture seemed to be from rain which infiltrated deeper in the ripped soil to avoid more evaporative loss than the unripped soil.
• A controlled traffic system will better protect the investment in deep ripping and extend the benefits. Deep ripping costs will also be reduced when the permanent tramlines are left unripped; seeding can also be easier with better flotation on permanent tramlines.

 

• Deep ripping enabled the crop to access about an extra 40kg of soil N/ha.
• The crop was as responsive to Flexi-N after deep ripping.
• There was no yield penalty from delaying Flexi-N application until the end of tillering. Deep ripping and Flexi-N were very profitable at this site.  

• Deep ripping did not affect depth to free water in 2018 or 2019; however these were decile 2 and decile 1 growing seasons at Kendenup West.
• Yield data was limited; however deep ripping may have produced a cultivation effect that slightly increased yield.
• Deep ripping is unlikely to be a reliable management option for waterlogging in forest gravel soil.

• Rip to below your compacted layer
• Ripping to 60cm reduced soil strength, and this effect continued into the second year after ripping
• Wheat yield response to the 60cm rip treatment paid for deep ripping in the first year
• Important to understand potential yield benefits of ripping before you rip

Deep ripping provided a 446 kg/ha wheat yield increase in 2017.

• The deep ripping site at Kojaneerup showed no consistent canola yield response in 2017
• Two consecutive frosts and extreme rainfall in late September reduced yield potential.
• Small differences in yield were not consistent within yield zones nor replicates.

The penetrometer measurements show that the nil treatment at both sites had a harder soil profile in the upper 20 cm at Hannafords (clay loam) and down to 35 cm at Jacobs. The reason the Nil treatment at the site of Hannafords shows lower resistance at depth is because this zone was waterlogged (water perched on the clay layer), showing that the ripping and spading have relieved some of the waterlogging. 

Ripping has done a very little to increase grain yields at the Frances site. The application of gypsum has generally increased grain yield by 15-20% over the untreated control treatment.  

The penetrometer measurements show that the nil treatment at both sites had a harder soil profile in the upper 20 cm at Hannafords (clay loam) and down to 35 cm at Jacobs. The reason the Nil treatment at the site of Hannafords shows lower resistance at depth is because this zone was waterlogged (water perched on the clay layer), showing that the ripping and spading have relieved some of the waterlogging.

Sub-soil compaction, caused primarily by the unmanaged movement of heavy machinery, is having a negative effect on grain yield and quality across the Geraldton Port Zone (as well other port zones in WA).  Compaction limits plant root growth, reduces plant available water capacity (PAWC) and in turn limits yield potential.

The profitability of a crop is dependent on the crop maximising the use of rainfall received and the PAWC of the soil is critical to this. This applies to all rainfall zones. Climate change however, has influenced the number of dry periods occurring during the growing season, so it’s more important than ever for crop roots to be able to explore the soil profile to the fullest possible extent.

Growers report that some soils on their property continue to underperform despite their fertiliser and system management strategy matching their soil type. The introduction of deeper deep-rippers to the region (550 – 700mm) has shown encouraging results, prompting growers to question current strategies and investigate the rippers as options for soil improvement.

In 2016 four growers within a 100km of each other currently employing deeper ripping strategies were asked to compare the performance of ‘deeper’ deep ripping (550-700mm) to standard deep ripping (250 – 350mm) and no ripping.  A full soil, plant tissue and grain yield analysis was performed at each site to gather information on the base site parameters and breakdown of how each soil responded to the treatments.

There was an increasing response to deeper ripping associated with a decline in rainfall at the sites (about 100mm variance across sites). To achieve the best return on investment growers are recommended to identify the sub soil constraints in their paddock before choosing the right tillage machine to alleviate them.

• Ripping below the hard pan (greater than 500mm) in pale sands, yellow sands and yellow loams in wheat or canola increases yield.
• Soil moisture probes show ripping deeper (below 500mm) allows more plant roots to access moisture deeper in the profile for longer in the season. Water infiltration also increase with depth of ripping.
• Leaving a firm even seed bed after deeper ripping is important to reduce seeding establishment issues.
• A negative yield response to deeper ripping in lupins on yellow sand was measured at Binnu in 2016.
• Crop yield response to ripping does vary depending on seasonal conditions and crop type therefore the economics of ripping must be considered over multiple seasons and timing of ripping in the rotation.

• Deep ripping to 500-600mm in coarse textured sandy soils increased yield by 21-66% compared to 6-24% with ripping to 300mm in wheat and canola in 2016 and 2017 in the Geraldton port zone.
• There was only a small yield response to ripping the red loam in 2016 and no difference in 2017.
• Soil moisture measurements and visual observations of plant root growth indicated deeper ripping allowed the plant roots to access more water from deeper down the soil profile. This is particularly beneficial in sandy soils that have a low plant available water capacity(PAWC) per 10cm down the profile therefore roots need access deeper into the soil profile to gain the same amount of water as heavier textured soils that have a higher PAWC per 10cm.
• Economic analysis found the higher cost of deeper ripping gave a positive return on investment up to $5/ha for every dollar invested at 3 sandy sites but not on the red loam where the return on investment was negative with a return of $0.63/Ha for every dollar invested. On the sand at Ogilvie there was a yield penalty in lupins in 2016, resulting in a negative return on investment which could not be recouped in the following dry season of 2017.
• If ripping below 400mm, consideration must be given to crop selection in year one (lupins are higher risk); leaving an even seed bed post ripping to reduce bogging and plant establishment issues; and managing weeds as due to poor competition and better access to water and nutrients can increase the weed burden as these factors can have a negative impact on yield reducing the return on investment.

Soils in the Wharminda and Stokes area of Eyre Peninsula were mapped and areas of micronutrient deficiency established by applying micronutrients (copper, zinc, manganese, iron, boron and molybdenum) in 24 factorial field experiments.

Fertiliser applications were made at the 1-2 leaf , tillering and booting stages.

• Grain yields were increased by copper application at 11 of the 24 sites.
• Zinc application increased yield at one site, manganese at one, iron at two and molybdenum at two sites, no increased due to boron application were recorded.
• Copper deficiency occurred in deep siliceous sands, calcareous sands, solodized solonetz and solodic soils with light brown sand at Wharminda.
• Zinc and manganese deficiencies were mostly confined to soils with a high carbonate content near the surface.
• Copper in the grain was a better indicator of deficiency than copper in the soil.
• Grain yield responses to copper application were indicated by grain copper of <2.5 ppm.

June 13th sown Gairdner produced yields in the range of 4.86 – 5.69 t/ha following canola stubble. With high soil nitrogen reserves (203 kg/ha N, 0‐90cm) recorded at sowing, there was a small but significant response to applied nitrogen (0.21 t/ha at 50 kg/ha N & 0.23 t/ha at 100 kg/ha N). There was a significant advantage to nitrogen timed during stem elongation (GS31‐33) over nitrogen applied in the seedbed.