• Treatments combining deep ripping with surface applied nutrition (synthetic fertiliser or chicken litter) delivered the highest marginal returns, ranging from $934 - $1249/ha over three years.
• Depending on treatment cost these delivered return on investment ranging from 142 – 521%, over three years.
• Placement of high rates of chicken litter (20t/ha) or matched synthetic fertiliser in the subsoil did not provide any yield increase over surface application.

• Incorporation method (deep ripping or spading) reduced plant establishment in both barley (2022) and lentil (2023) as a result of soft and uneven seedbed conditions. However, later in the season NDVI showed the crop had recovered with values similar or higher compared to the control.
• The application of lime in 2022 increased NDVI in all incorporation treatments by an average of 10% on 1st September in the following season lentils.
• In both seasons grain yields were increased by an average of 0.7 t/ha in barley and 1.03 t/ha in lentil from spading and deep ripping. However, this was not influenced by the incorporation of 10.7 t/ha Kulpara lime.
• Soil sampling one year after the trial was established generally showed lime with and without incorporation increased group E/F rhizobia levels compared to the control.
• Long-term monitoring is required to understand the movement and benefit of lime incorporation at depth. 

• Lentil crop safety varied significantly between acidic and alkaline sands in 2021 trials, with the use of Reflex®, diuron, metribuzin and terbuthylazine herbicides, with alkaline sand sites incurring more herbicide damage than acidic sand sites.

• Crop damage with Reflex® herbicide on alkaline sands was rate responsive, with yield loss in a trial at Bute increasing from 17% when applied at 0.5L/ha to 54% when applied at 1L/ha.

• Crop damage on alkaline sands was cumulative where Reflex® was applied in combination with a group 5 herbicide, such as diuron. In a trial at Alford on an alkaline sand, yield loss to either diuron or Reflex® was 20%, increasing to 52% yield loss when applied in combination.

• Seasonal variation, including higher rainfall post-seeding in 2021 may have been a contributing factor in higher level of crop damage in alkaline sandy soils.

• Effective control of broadleaf weeds such as bifora, common sow thistle, Indian hedge mustard, wild turnip and capeweed, including populations resistant to Group 2 imidazolinone herbicides, was achieved with Reflex® (Group 14 herbicide).

• Control of various broadleaf weeds was achieved in lentil using Reflex® in combination with other registered herbicides including Group 2, 5 and 12 herbicides. However, crop safety to these combinations varied between herbicides and their doses, and soil type.

• Herbicide strategies on high-risk alkaline sandy soil types needs careful planning to balance between avoiding crop damage and achieving adequate weed control. Rate of Reflex may need to be adjusted near the middle of the rate range in some soil types to find the right balance of crop safety and weed control. 

• Varietal resistance plays an important role in managing wheat powdery mildew. The variety Grenade CL PlusA (MS) had less powdery mildew infection in the untreated than Chief CL PlusA and ScepterA (SVS) treated with a two-spray fungicide strategy.
• Wheat powdery mildew resistance mutation frequency increased from 2019 to 2021. In the northern Yorke Peninsula region in 2019, more than half the paddocks surveyed had no group 11 QoI (strobilurin) resistance mutation, whereas in 2021, all 30 paddocks sampled had some level of resistance mutation with the median resistance frequency increasing from 0 to 19%.
• Group 11 QoI resistance mutation has been detected at lower levels in the central Yorke Peninsula and Mid North regions in 2021.
• In a fungicide product trial, the application of group 11 QoI fungicides increased the frequency of resistance mutation from 19% in the untreated control to 48.5% on average across QoI treatments.
• The presence of group 11 resistance mutations meant that the performance of group 3 + 11 fungicide mixtures was generally not any better than the straight group 3 (DMI triazole) fungicides.
• Group 7 SDHI fungicides did not provide any additional control to the standalone group 3 DMI fungicides when applied in product mixtures. This is due to poor efficacy of group 7 fungicides on wheat powdery mildew, with no resistance to this fungicide group identified in these powdery mildew populations.
• Mutation at Cyp51 is a gateway mutation that infers reduced sensitivity to the group 3 DMI fungicides is likely, though the actual mutations conferring resistance are not known. High frequency of the Cyp51 mutation has commonly been encountered at trial sites, yet the group 3 DMI fungicides are currently providing the best fungicidal control, albeit incomplete control.

• All sandy sites were responsive to both physical interventions and CL addition. The size of the response varied for each site ranging from up to 127% on the most productive sand (North hill top) up to 191% on the least productive sand (South mid slope).
• The grain yield response to physical incorporation method (deep ripping and spading) and CL was generally greater than 10%, but the ranking of specific treatments varied within each of the three sandy soil trial sites.
• In the absence of CL, there was no benefit from using long versus short inclusion plates in year one. However, in year two both the North sites had improved grain yield from the use of long inclusion plates suggesting greater longevity from the inclusion of more top soil.   
• In the first season, spading resulted in a soft soil surface and made seed placement difficult. Consequently, the wheat crop struggled to emerge and impacted crop performance. However, in the second season the soil had consolidated and no issues with seed placement or crop establishment occurred.
• Results from the depth of ripping trials have shown responses to ripping 40-60 cm deep in all six site years. No yield responses were measured from a ripping depth of 20 cm.

• All sandy sites were responsive to both physical interventions and CL addition. The size of the response varied for each site ranging from up to 127% on the most productive sand (North hill top) up to 191% on the least productive sand (South mid slope).

• The grain yield response to physical incorporation method (deep ripping and spading) and CL was generally greater than 10%, but the ranking of specific treatments varied within each of the three sandy soil trial sites.

• In the absence of CL, there was no benefit from using long versus short inclusion plates in year one. However, in year two both the North sites had improved grain yield from the use of long inclusion plates suggesting greater longevity from the inclusion of more top soil.

• In the first season, spading resulted in a soft soil surface and made seed placement difficult. Consequently, the wheat crop struggled to emerge and impacted crop performance. However, in the second season the soil had consolidated and no issues with seed placement or crop establishment occurred.

• Results from the depth of ripping trials have shown responses to ripping 40-60 cm deep in all six site years. No yield responses were measured from a ripping depth of 20 cm.

• In season one lentil grain yields were generally low (0.16 t/ha – 0.62 t/ha) in the sand, straw and gypsum amelioration trial. The high sand application rate (1300 t/ha) was the only treatment to improve lentil grain yield compared to the control. 

• This season larger differences among the sand and straw rates are emerging. Sand rates above 650 t/ha and straw rates above 6.6 t/ha resulted in wheat grain yields of 1.95 t/ha – 2.42 t/ha compared to the control 0.67 t/ha. 

• Wheat yields following various crop type/varieties sown in 2022 to manage salinity ranged from 0.51 – 0.99 t/ha. Wheat yields following canola and field pea were higher compared to wheat following wheat, triticale or barley. 

• There was a link between wheat grain yield this season and plant cover from the various crop types/varieties at harvest last year. Crop types which had <40% plant cover at harvest resulted in lower wheat yields the following season. 

• Crop establishment (total number of plants/m2) was not impacted by any of the non-aggressive strategies targeted at alleviating non-wetting sands. This was not unexpected as the site was not considered water repellent based on molarity of ethanol droplet (MED) testing.
• Grain yield in the spading treatment was 5.2 t/ha (248% higher) compared to the standard treatment (2.1 t/ha). This highlights there was a subsoil constraint at this site (high soil strength) and the spading treatment which used a working depth of 30 cm alleviated this problem, resulting in improved grain yields.   
• The CV (variation in plant number) for crop establishment was negatively correlated to the plant population at this sandy site. On row and deep seeding reduced the CV, implying improved and more even crop establishment.
• The use of wetters and different press wheels reduced the CV slightly, but none of these increased grain yields.
• While site selection was undertaken based on anecdotal evidence of a history of non-wetting, the MED test was unable to confirm these observations. The sensitivity of this test will be explored on a wider range of local non-wetting sands in 2024.  

• A lack of grain yield response to lime rates and products trialled at Bute is most likely due to the slightly acidic (pH CaCl2 4.8 – 6.1 in the 0-30 cm) nature of the site. However, it is important to monitor soil pH profiles similar to this for pH declines in the future.
• Grain yield response to incorporation method has been variable across the seasons. Lentils showed the greatest benefit in both 2020 and 2023 seasons, while the cereal yields have been unresponsive.
• Treatments which incorporated lime by spading, increased molybdenum tissue concentration (0.35 – 0.37 mg/kg) compared to the no-till control (0.24 mg/kg) in barley in year four.
• Predicta rNod samples taken four years after the trial commenced showed, the application of lime (regardless if surface applied or incorporated) has increased the level of group E/F rhizobia persisting in the soil.
• Both trials contained treatments which have increased soil pH since lime was applied. However, the depth where this pH change has occurred was different in the lime product compared to the lime incorporation trial.

• Much of SA experienced above average spring rainfall with the growing season extending into November (71 mm received) at Bute, SA.    
• Wheat grain yield and protein levels were high for N rates ranging from 72 kg N/ha to 143 kg N/ha.  
• All N treatments resulted in a negative partial N balance indicating soil organic N was mined. This occurred to a smaller extent in the YP BOM (-15 kg N/ha) and district practice (-27 kg N/ha) treatments.
• Grain yield response to applied N (15 - 143 kg N/ha) was up to 1.51 t/ha. Surprisingly high yields (6.46 t/ha) were achieved in the absence of applied N. This was likely driven by high starting soil mineral N (legume stubble) and high rates of mineralisation in the extended growing season.

• In the fourth trial season lentil grain yield benefits were observed from spading and lime treatments. Addition of lime (2200 kg/ha or 6600 kg/ha) and mixing with low, medium or high uniformity were the highest yielding treatments ranging from 3.36 to 3.69 t/ha.
• Lime rate and spading have had variable response on NDVI across four years. 
• In the first three years of the trial plant establishment has generally not been affected by lime rate, spading uniformity or deep ripping.
• Lentil tissue tests in year four revealed increased Mo levels (>0.3 mg/kg) in treatments where lime was applied.
• Soil samples taken in 2022 showed both the high and low uniformity treatments plus lime have increased soil pH compared to the control. The high uniformity has had the greatest impact on soil pH across the 5 to 30 cm sampling depths. 

• Currently registered fungicide products from groups 3, 7 and 11 have not provided high levels of powdery mildew control in several field scenarios tested. The industry would benefit from access to alternative modes of action that have specific activity against wheat powdery mildew.Where multiple pathogens are present, multiple modes of action may be necessary that provide good control of all pathogens.

• Low level varietal resistance, i.e. MSS is enough to significantly reduce WPM infection, compared with highly susceptible SVS varieties.

• At Malinong, SA currently registered products from fungicide groups 3, 7 and 11 did not provide high levels of powdery mildew control. This is consistent with previous findings from trials conducted in this project and SAGIT project TC120 across 2020 to 2022.

• Products from alternative modes of action (group 13) provided high levels of powdery mildew control. Septoria infection was also present at this site and must be taken into consideration when interpreting these results. 

• There was no or low levels of powdery mildew infection at the Bute, SA and Katamatite, Vic trial sites. These trials did not generate significant new data towards powdery mildew management strategies. 

• Field-based sensor surveys are providing some clues for differences in landscape position that might be important in powdery mildew development. Initial results reported here show temperature differences in July/August may be contributing to the differences in the level of powdery mildew infection. However, the results from one season of field monitoring are not sufficient to answer all research gaps. 

• Last season a number of regions were resampled (central and northern YP, mid-north, Victoria) for resistance testing to look at the change in G143A mutation frequency overtime.