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.

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

• 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.

• The rotation with canola as a single break crop (canola– wheat–wheat rotation) had the highest average gross margin ($529/year) across three years.
• The profit/cost ratio was the highest when canola was used as a single break crop (2:8) and the lowest for all brown manure treatments as well as continuous cereal without nitrogen input.

• Compass, Fathom and Scope CL were good competitors with weeds, which is consistent with previous years’ findings.
• Hindmarsh and Spartacus CL are poor weed competitors.
• The advantage of sowing earlier in order to increase crop competition failed to improve the competitiveness of La Trobe given the high spring rainfall.

The risk of stem frost damage can be minimised by using winter wheats if sowing prior to 20 April. Spring wheats should be kept within 5-7 days of their optimal sow date. If appropriate, risk of BYDV should be managed by backing up imidacloprid seed dressing with foliar insecticides at the start of tillering if aphids are present. New winter wheat cultivars are in the pipeline and are likely to have significant yield advantages over current ageing material.

• There is no evidence to support growers grading seed into different size categories and sowing the smaller seed.
• In one trial in 2015, sowing seed of different size classes did not significantly influence the yield of PBA NasmaA. Insufficient data is currently available to make a recommendation either way on this practice, but there was a trend towards reduced size of harvested seed and yield from sowing smaller PBA NasmaA seed.

• 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.

• The effects of zinc supply in subsoil were examined in three genotypes of Brassica napus in a glasshouse experiment.
• The topsoil was supplied with zinc in all treatments whereas zinc was either supplied or omitted from the subsoil.
• Supplying zinc to subsoil significantly increased the root growth in the lower zone, markedly decreased the number of aborted and unfilled pods/plant, number of seeds/pod, individual seed weight and overall seed yield.
• Subsoil zinc also significantly increased the zinc concentration and zinc content of seed and improved the ratio of zinc uptake by seed to total zinc uptake by seed and shoots.

Field peas can respond to the use of rhizobia innoculants.

Chickpeas need to be inoculated in paddocks which have not had chickpeas before.

The season was too dry to see the benefits of inoculating legume seed with rhizobia.

• Insect prest pressure was generally low in Victoria and Southern NSW for 2001.
• There was no significant yield differences between the different pest control treatments, with the site mean being 4.92t/ha.
• Selective insecticides promote and encourage beneficial species which can be useful in combating harmful pest species attacking crops.

These trials demonstrate that certain crop species and cultivars such as barley, oats and grazing wheat, can
suppress weeds effectively at standard establishment rates. This may be due to their ability to compete
effectively with weeds for valuable resources, or their potential to exhibit allelopathic effects associated either
with the crop or remaining residues following harvest.

• The seed catcher treatment reduced the ryegrass seed bank from 2007 most effectively
• Delaying sowing in 2008 from the 29th May until the 6th June decreased the ryegrass population by 55%.

• A combination of chemical and non-chemical weed control strategies can extend the life of herbicides and improve the sustainability of intensive cropping systems.
• Windrow burning, crop topping and chaff carts are options which can reduce the ryegrass seed bank without any yield penalty.
• Cutting a cereal crop for hay for one year can significantly decrease ryegrass levels in the following crop.

• An integrated weed management (IWM) approach was used incorporating integrated Harrington Seed Destructor (iHSD), herbicide, hand picking, crop rotation and early grazing opportunities
• After seven years wild radish numbers were controlled on paddocks that previously had high densities 
• Between 2018 and 2020 the radish population was reduced by 71%

• Integrated weed management is the best approach for long-term control of herbicide resistant annual ryegrass.
• The most effective cultural control method trialled was mouldboard ploughing which was significantly better than stubble.burning or direct sowing into retained stubble in terms of in crop weed numbers.
• Sakura + Avadex Xtra IBS herbicide regime achieved the best control of annual ryegrass later into the season.
• Crop establishment, wheat yield and grain quality were not affected by the choice of weed control method in this trial.

• Pre-emergent weed control with Sakura reduced annual ryegrass populations by 85-97% compared to the control

• Combining Sakura pre-em with Boxer Gold at GS11 resulted in 97% weed control 180 days after sowing

• Sakura provides robust pre-em weed grass control and can be used as one element of an integrated weed management approach

• Other practices that can form part of an IWM strategy include paddock selection, cultural control, grazing, land fallowing and chemical rotation

• Continuous cropping and a reliance on pre-sowing weed control measures is not an effective way to manage herbicide resistant annual ryegrass over the long term.
• The increase in weed numbers over time can be limited by adopting an intensive and high cost herbicide strategy, but this will not deplete the seed bank.
• Increasing annual ryegrass density was associated with decreased grain yield.

• 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.

Herbicide strategy 1 (HS1), which was based on atrazine pre-sowing followed by clethodim (Select) post-emergence reduced ryegrass plant density relative to the untreated control by 57%. However, use of propyzamide pre-sowing, followed by atrazine and Select + Factor (HS 2) increased ryegrass control to 77%. Canola variety had a significant effect on ryegrass spike density (P=0.002). When averaged across the sowing dates and herbicide strategies, ryegrass growing in HyTTec Trophy produced 52 spikes/m2 as compared to 78 spikes/m2 in Bonito (33% reduction). HyTTec Trophy is a new hybrid triazine tolerant variety from Nuseed, which is known for high early vigour. Herbicide strategies also had a significant effect on ryegrass spike density (P<0.001). Ryegrass grown without any selective herbicide treatment (control – HS3) produced 128 spikes/m2 as compared to 40 spikes/m2 in HS1 and 29 spikes/m2 in HS2. This works out to 69% reduction in HS1 relative to the control and 78% reduction in HS2. Herbicide strategies had the largest effect on canola yield (P<0.001). HS1 and 2 produced canola yield of around 0.8 t/ha, which was almost 50% greater than the yield obtained in the control.

• Positive yield responses from the control of yellow leaf spot (YLS) were recorded despite disease levels not exceeding 10% on the top three leaves in this wheat-on-wheat rotation position.
• For the second year in succession there was a significant yield increase (0.12t/ha mean of two fungicide products) from two fungicide applications made at the late tillering stage and the second node stage (GS25 and GS32).
• The yield response from two fungicides corresponded to significantly better disease control than the untreated control and increased the crop canopy greeness.
• Although single fungicide timings produced little or no evidence of YLS control, significant yield increases were measure (0.13-0.14t/ha).
• Nitrogen timing (application of 40kg N/ha at either tillering (GS22) or first node stage (GS31)) had no significant effects on disease levels, yield or quality.

• The level of yellow leaf spot (YLS) control achieved with fungicides applied at tillering (GS22) and third node stage (GS31) in wheat-on-wheat was poor (less than 50% in most assessments).
• Fungicide applied at the third node stage (GS33) was more effective at preventing YLS infection on the top three leaves of the crop than when applied at tillering (GS22).
• Fungicide applied at the third node stage (GS33) generated a significant (0.44t/ha) yield increase over the untreated crop, whereas the equivalent fungicide applied at tillering (GS22) gave no yield benefit.
• Applying fungicide at both tillering (GS22) and third node stage (GS33) offered no advantage over a single application at GS33.
• Nitrogen application at tillering or first node had no effect on yield.
• There was no significant difference in product performance between Tilt and Prosaro.

• 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.

The later maturing feed wheat Mackellar was significantly lower yield than the earlier AH category variety Chara, with mean yields of 2.35 and 2.52 t/ha respectively. Much of this difference was due to the poor performance of Mackellar under the seedbed nitrogen application, since when compared at the later nitrogen timing alone, the mean yields were 2.55 and 2.60t/ha for Mackellar and Chara respectively. Fertilising with upfront nitrogen had less detrimental effect on yield with an early maturing variety with lower tillering capacity than it did with later maturing wheat (Mackellar) that had a longer tillering window.

Dry sowing resulted in the poorest weed control at seeding and as a consequence this treatment was the weediest later in the year.

• Spray-seed drift during shielded spraying damaged the lupin plants in this trial.
• Lupins yielded well when sown in rows 50cm apart.

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.

• The results presented in this report are from the first year of a three-year study that investigates the effect of break-crop sequences on wheat grain yield. The site was selected due to its high background levels of ryegrass control, and crop rotation treatments have been designed around weed control as the main rotational factor.
• Grain yield was relatively low compared to the growing season rainfall of 253 mm. Grain yield was affected by severe frost that occurred during grain fill.
• This project will continue with the second crop in rotation for the 2017 season, followed by wheat across all plots in 2018 to assess the benefit of a stacked rotation for subsequent wheat grain yield.

The trial will be going into its 3rd year in 2018 and all trial plots will be sown into wheat. The aim is to determine the difference in grain yield for wheat following a range of single or double break crop rotations, compared to continuous wheat. The site was established in 2016 on a paddock that had very high level of ryegrass that was affecting crop production. This area around this trial has been in pasture for 2017 as the comparison farmer solution for the issue.

• Understanding key drivers and processes in controlling awnless barnyard grass (Echinochloa colona), feathertop Rhodes grass (Chloris virgata), fleabane (Conzya bonariensis L), windmill grass (Chloris truncata) and sowthistle (Sonchus oleraceus L).
• Investigating the impact on weed control of pupae busting and the potential impact of removing this tillage operation.
• Demonstration of integrated weed management principles, including controlling ‘escape’ weeds and the impact on seed set, to encourage industry to adopt the research outputs.
• Glyphosate resistance is emerging in cotton farming systems.

• 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 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.

This demonstration has highlighted the impact poor nozzle selection can have on herbicide efficacy. Generally all post emergent herbicide applications are made with the one nozzle type, as a result, less than optimal weed control may occur. It was found that selecting a nozzle with a fine droplet pattern and good coverage gave best results for contact herbicides (Brodal and Bromoxynil) and for those poorly translocated within plants (Group A herbicides). For LVE MCPA, which moves readily through the plant, coverage is not essential allowing larger droplet size nozzles to be used without losing efficacy. This is important for preventing drift, as phenoxy herbicides such as LVE MCPA are susceptible to drift. Understanding how herbicides work will allow for better nozzle selection and more cost effective weed control.

This demonstration has highlighted the impact poor nozzle selection can have on herbicide efficacy. Generally all post emergent herbicide applications are made with the one nozzle type, as a result, less than optimal weed control may occur. It was found that selecting a nozzle with a fine droplet pattern and good coverage gave best results for contact herbicides (Brodal and Bromoxynil) and for those poorly translocated within plants (Group A herbicides). For LVE MCPA, which moves readily through the plant, coverage is not essential allowing larger droplet size nozzles to be used without losing efficacy. This is important for preventing drift, as phenoxy herbicides such as LVE MCPA are susceptible to drift. Understanding how herbicides work will allow for better nozzle selection and more cost effective weed control.

All treatment gave significant responses to grain protein as compared to the control. 

• 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.

Bannister had the highest grain yields with 9.00 t/ha.

Grazing did impact on yield in Bannister, but not Durack or Yallara.

Additional N above the control did not increase grain yields. Based on the trial results, Bannister nitrogen requirement was 25 kg N/t, whereas Yallara and Durack required 35 kg N/t.

Dry matter harvested (simulated grazing) at around GS31 ranged between 0.81 and 0.99 t/ha (NS)

Wimmera had the greatest yield loss in the presence of weeds and produced the highest weed yield. Hindmarsh also produced the same weed yield. Both of these varieties should not be sown into weedy paddocks unless there is a good management strategy. Scope, Buloke and Compass were identified as very competitive varieties, with the least amount of yield loss and weed seed production. Generally, the presence of weeds reduced barley yields by 1.4t/ha on a 5.4t/ha crop (mean of all varieties).

• Two lontrel resistant biotypes have been identified in overseas vetch populations.
• Risk of resistance in Australian farming systems is low, but management practices to avoid lontrel resistant vetch should be implemented.
• Be more wary of wild vetch populations as opposed to volunteer vetch.

Yield loss of 0.1-0.5t/ha was observed in some SFNB susceptible varieties at Horsham that had two fungicide applications. The Quambatook site suffered significant yield loss but this was due to a combination of SFNB and an additional factor (possibly crown rot). It is unlikely that a single application of foliar fungicide would have provided effective control of SFNB and prevented yield loss if applied after GS39 or to MS or better rated varieties.

Zinc needs to be applied as part of the fertiliser program every three to four years in the Wimmera and Mallee. The use of zinc as a seed dressing or foliar application will only be beneficial when the paddock has had a poor zinc history. In trials at the Rupanyup site where zinc had been applied 2 out of the last 5 years there were no yield benefits of adding more zinc even to responsive crops such as faba beans and lentils.

• JumpStart is phosphate inoculant containing naturally occurring soil fungi
• Trial showed no significant difference in JumpStart treatments
• Significant yield increases achieved with increasing phosphorus rates
• DGT test results suggest JumpStart increases plant available P residual for following crop

• Summer weed control is not a luxury item and should be considered an essential expense.
• The financial reward of timely summer weed control far outweighs the outlay and this was again proven in 2006.
• Expenditure on summer weed control can be minimised if weeds are sprayed early.

The use of a Speed tiller to incorporate stubble did not appear to have any negative impacts in the mixed farming systems in the medium rainfall zone in the South-East of South Australia in a very dry season. There was high paddock variability, due to moisture stress, which would have impacted the results.

KI’s 7 golden rules for successful establishment

•  Good weed control is absolutely critical – it’s a waste of time seeding if you don’t get weed kill.
•  Apply broad spectrum insecticides pre-seeding.
• Seed in early Spring.
•  Seed at 2kg/ha.
•  Ensure good seed soil contact.
•  Allow the plants to become well established before grazing.
•  Continually monitor the paddock, after seeding for insects and pests and during the first graze to ensure stock are not pulling up runners.

• Kikuyu has the potential to become a valuable addition to pasture mixes on parts of KI
• Kikuyu may provide many economic as well as environmental benefits
• Early spring sowing plus weed and insect control is essential for successful establishment (and the odd rain dance won’t go astray either!)
• Kikuyu is less likely to become an environmental weed if the adjacent native vegetation is fenced and is in good condition.

• Kikuyu has the potential to become a valuable addition to pasture mixes on parts of KI.
• Follow the nine golden rules for success – weed, insect and vermin control, good seed/soil contact, shallow seed at 2kg/ha in spring, don’t graze until well established, use N fertiliser or legumes.

• Weed control is essential for effective kikuyu establishment.
• Two sprays of round up is the ‘safest’ bet although you do lose some grazing value and may have difficulties with seeding at the optimum time if the paddock is too wet to spray early.
• Further work is required to quantify the benefits of application of TM 21 on kikuyu pastures on KI.

• Weed control is essential for effective kikuyu establishment.
• Two sprays of round up is the ‘safest’ bet although you do lose some grazing value and may have difficulties with seeding at the optimum time if the paddock is too wet to spray early.
• Further work is required to quantify the benefits of application of TM 21 on kikuyu pastures on KI.

• 2015 - Plots with-out lime were consistently lower yeilding than plots with lime irrespective of incorporation treatment. Threatments with incorporation tended to have higher yield than where lime is left on the surface.
• 2014 - sowing setup remains the weakest link when using deep tillage. Depth of sowing is critical and fifficult to control on ameliorated soils. A good establishment density is critcal for reducing erosion potential at both ends of the season.

This demonstration investigated knockdown weed control options prior to sowing. For the knockdown control of ryegrass, canola and wild radish prior to sowing, glyphosate is quite effective and no additional herbicides are generally required. Glyphosate is weak on marshmallow and a group G herbicide is required as a mix with the glyphosate. To reduce the risk of group M (glyphosate) resistance developing in ryegrass it is strongly recommended to use the ‘double knock’ approach (glyphosate followed four to seven days later by SpraySeed®) on at least some paddocks every year.

• It is no longer a question of whether ryegrass will become resistant; it is when! 
• Double knock was the most effective treatment for managing this ryegrass population  (98% control).
• Alternative crop options should be integrated into the rotation to manage weeds and reduce the reliance of glyphosate. 
• High water rates, spraying closer to evening and no later than 7-10 days after the initial knockdown are essential when using Paraquat.

• Following drought affected cereals, labile P concentration was greater in the crop row than in the inter row.
• There is potential to exploit carry over P following 2006.
• In addition this may also have implications for those with auto steer systems with 2cm accuracy to seed into higher concentration of P in last years failed or low yielding crops.

Late (Z39+) application of N resulted in yield and protein increase over the control.

Crop yields were dissapointing due to the frost in late October.

Key points to be taken from this trial are, ensure early sprays are applied when Wheat Leaf Rust is detected. All fungicide treatment with an early treatment resulted in a significant yield benefit. it is important to take into consideration the cost of any particular fungicide treatment and the potential yield response.

In the post emergent treatments a range of herbicides produced very good control of all oilseed and legume crops included.

• In the post-emergent treatments a range of herbicides produced very good control of all oilseed and legume crops included.

• In the post emergent treatments, a range of herbicides produced very good control of all oilseed and legume crops included.

• In the post emergent treatments a range of herbicides produced very good control of all oilseed and legume crops included.
• Lucerne was significantly damaged by almost all herbicides applied.

• Simazine and metribuzin produced more crop effect compared to normal, especially in lentils. 
• For all the PSPE application treatments 50% more product significantly increased the crop damage.
• The double knock of glyphosate followed by SpraySeed gave excellent control.

• New post emergent broadleaf herbicides Torpedo, Conclude, Precept and Velocity generally gave good control of pulses or canola.
• Pre-emergent grass herbicides had no effect on the growth of pulses or canola.

2018 Season 

• While growing season conditions were dry and grain yields were low and therefore not profitable, both Bolt lentils and Gunyah field peas yielded highest of the 5 break crop species grown at the Salmon Gums demonstration site. Soil boron levels were relatively high at this site.
• Following waterlogged conditions in August, Bonito canola out yielded the 4 four legume break crop species grown at the Gibson demonstration site, with Samira faba beans a close second.
• The addition of an extra 72 Units of nitrogen (171L Flexi-N delivered in 3 incremental applications) to the 5 break crops at the Gibson demonstration site resulted in significant increases in yield and earnings before tax profit in both Bonito canola and Samira faba beans but made little difference to the performance of PBA Strikers chickpeas, Morava vetch and Jurien lupins. The addition of extra nitrogen to Faba beans lifted yield by an average of 0.763t/ha taking it to 2.473t/ha which was close to the average yield of un-topped-up canola (2.169t/ha).
• In terms of earnings before tax, the faba bean crop was the most profitable of the 5 break crops grown at Gibson. It is important to note though that the $800/tonne price seen for faba beans in February 2018 was well above both the five and ten year average for this crop.

2019 Season 

• Annual rainfall was well below average in 2019 at all 5 demonstration sites in the Esperance Port Zone and an unprecedented frost event in September affected crop flowering at the Ravensthorpe, Salmon Gums and Beaumont sites. It’s important these seasonal conditions are factored to in to interpretation of legume crop performance at these sites.
• Poor growing conditions at the Ravensthorpe demonstration site resulted in very low yields and none of the break crops grown were profitable. The State Government declared part of the Ravensthorpe Shire as water deficient on 7th May 2019 and further parts of the Shire on 13th February 2020.
• Reasonable rainfall in August stimulated germination of broadleaf weeds resulting in a higher than ideal weed burden in all break crop species strips at the Ravensthorpe site. This highlights the limited control options available for late weed germination in legumes.
• At the Coomalbidgup demonstration site while lupins yielded highest of the break crop species grown, they were not profitable, making an EBT tax loss. Chickpeas were the only profitable break crop species grown at this site; lower seasonal rainfall meant the waterlogging conditions that commonly prevail at this location were not a constraint on chickpea yield. An average rainfall year would likely result in chickpea yield losses due to their susceptibility waterlogging.
• Dry conditions at the start of the season at Coomalbidgup reduced herbicide efficacy but the site did not have a high background broadleaf weed pressure so competition was unlikely to have greatly reduced crop yield.
• Poor growing conditions at the Beaumont demonstration site, which entailed a dry start, a severe frost at flowering and a very dry finish resulted in none of the 5 break crops grown performing profitably. The dry start at this site affected plant establishment of the chickpeas and faba beans in particular. Seeding equipment issues handling the large seed size of the faba beans also reduced establishment of the beans.
• Poor growing conditions, which entailed 2 dry preceding years resulting in very low subsoil moisture at the start of the season, a dry start, a dry growing season, a severe frost at flowering and a dry finish meant that Scepter wheat yields were below average at the Salmon Gums demonstration site. There was no significant difference in wheat yields achieved between the 2018 break crop species treatments. Scepter was profitable after each of the 2018 break crop species except in those replicates following vetch. Wheat after lentils were most profitable with an EBT return of $50/ha, followed by wheat after field peas at $34/ha.
• At the Gibson Demonstration Site wheat following vetch grown in 2018 yielded highest and was therefore the most profitable. Wheat following faba beans and lupins grown in 2018 yielded next highest; their yields being statistically similar. Wheat in replicates following 2018 canola and chickpeas were similar and yielded lowest of the 2018 break crop species treatments.
• Wheat yield in replicates that received an additional 171L/ha of Flexi N in 2018 yielded higher than those that did not and as such were more profitable.
• Tissue test data and wheat yields achieved at the Gibson site suggested nitrogen carryover from 2018 to the 2019 cropping season had occurred. This was not reflected in the pre-seeding soil test data demonstrating the significance of low soil moisture in impeding soil nitrogen mineralization. These results emphasise the importance of understanding mineralization when interpreting soil test results in dry conditions and the merits of coupling autumn soil testing with in-crop tissue or soil testing to support in-crop nutrition decisions.

Lentils are best to be used as the last legume crop in a rotation as the volunteer lentils are hard to control in other legumes.

• Growers and advisers should be vigilant in applying protective fungicide sprays in chickpea and lentil crops for ascochyta blight.
• Many current and minor use permit fungicides trialed at Hart in 2017 provided good preventative control (less than 10% of plants infected) for ascochyta blight including; chlorothalonil, Aviator Xpro, Cabrio and Captan.

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

• Most varieties yielded did not incur yield loss from crop topping at the recommended timing indicating that they were well suited to crop topping at the recommended timing for rye grass control in 2014 where the season finished rapidly due to dry conditions.
• As found in previous seasons there is not always a direct correlation between variety flowering and maturity timing and yield loss due to crop-topping.

The significant detrimental effect of P Pickle T on lentil yield was thought to be due directly to the seed treatment rather than due to a reduction in disease control.

• Early sown lentils consistently out-yielding those sown later, as the heat wave event in early
  November compromised yield of late sown lentil crops by terminating seed fill prematurely.
• The 2009 data was inconclusive in determining whether foliar fungicides for BGM control
  can be delayed until after the canopy closure stage in situations where conditions are not
  conducive for disease development at canopy closure (ie less than 10oC at night and 18oC
  during the day).
• The rapid finish to the season favoured early maturing varieties PBAFlash and CIPAL610 at
  both sites, averaging 5-32% above site means across sowing dates.
• Canopy closure sprays with follow up sprays dependent upon disease observation were
  successful in reducing BGM in all varieties tested at Paskeville, even at the early sowing
  date.

• The late break (11 June) and prevailing seasonal conditions were unfavourable for the spread of botrytis grey mould at both sites in 2005
• Traces of botrytis grey mould were found at both sites but had no impact on yield. A late season ascochyta blight outbreak did occur at Melton however control sprays may have been applied too late to induce a fungicide response.
• No significant difference was recorded between any of the different fungicide spray strategies between varieties or at different sowing times.

Soluble herbicides utilised in controlling broadleaved weeds in lentils can have significant impact on growth. Ensuring that soil throw is minimised back into the seed row is paramount. Also understand soil moisture levels prior to applying some herbicides and the impact this factor will have on uptake and persistence

Depending on nutrition demand and soil nutrient levels, foliar applied products can assist in increasing yield. Primarily in a sand loam soil at this site, Sulphur products appeared to increase yield

• Results from this experiment and previous research have proven that lentils can be successfully grown in southern NSW with sound agronomic planning and management.

• Across all varieties tested there was no significant difference between the 4 May and 20 May sowings, which validates the current sowing window recommendation from late April to mid May for the western region of southern NSW. Previous experiments have shown yield decline with a late May sowing.

• PBA Hurricane XTA, PBA Jumbo2 and PBA Bolt were the highest yielding commercial varieties, while PBA Ace was significantly lower yielding in this experiment, which is not consistent with previous research.

• There was a significant reduction in seed weight when sowing was delayed for all varieties except PBA Ace, which showed no significant effect.

• The low mean yield at this site (0.69 t/ha) was largely attributed to drought, and was exacerbated by late sowing conditions and suspected herbicide damage.
• Small yield and normalised difference vegetation index (NDVI) increases closely reflected increases in seedling density. 
• PBA Giant and PBA Jumbo2 produced more grain and green foliage cover, closely followed by PBA Ace. These ranking reflect the long term, multi environment trial (MET) yield analysis for lentil varities for this region (Figure 5).
• Care should be taken when applying and incorporating herbicides on acidic, light textured soils, particularly when straw is present. Under these conditions, it is advisable to sow deeper to position seed below the herbicide band. 
• Furher lentil sowing rate investigations are required in this region to better understand variety responses to plant density, earlier sowing, season conditions and different environments.    

• Desiccating lentil crops was critical in 2010 to minimising losses by allowing an earlier harvest, prior to the heavy rainfall events. Rainfall affected crops yielded up to 50% less.
• The earlier maturing varieties PBA Flash and PBA Blitz offer higher yields in drier years but not necessarily in long seasons such as 2010.  
• In the Mallee, PBA Blitz offers good disease resistance which improves reliability and yield and its medium large seed makes it attractive for export.
• Late in 2010 in the Mallee, disease and virus were observed. These may have resulted in higher seed infection and inoculum levels. Be prepared for higher disease and virus levels in 2011.

• Ascochyta blight- and botrytis grey mould-resistant red lentil variety, Nipper, available for higher rainfall areas.
• Green lentil, Boomer, available for farmers but must be harvested early to maximise yield and seed quality.
• Good lentil management is beneficial in most years, irrespective of rainfall.