30 years after application, water soluble P leaches to depth on grey sands but is still effective for the growth of deep rooted blue lupins.  On the one-hand, the citrate-soluble P in C-500 releases more slowly through time and so has a longer term residual effect than water soluble P. On the other hand, higher rates of C-500 are required than superphosphate to reach maximum yield when soil P levels are low.  It is less likely to leach and so pollute ground waters. If cheap enough, C-500 could be used as a maintenance P fertiliser.  Much work is still to be done on this trial site.

Vetch is a multi-purpose crop; its versatility allows decisions about its end-use to be made during the year (grain, hay/silage or green manure/grazing) and also can be used as a management tool against resistant weed development. Vetch can improve soil fertility by returning organic matter to the soil, increase yield in the following crop by means of nitrogen fixation and reduce disease and insect risk for the following crop. Two new varieties; SA-34823 and SA-35103 are set for release in spring 2013.

Andrew’s management of water repellence demonstrates that a strategy of affordable progressive amelioration and better sowing methods for the rest of the crop can be a successful and profitable approach for managing soil water repellence. On-farm testing of water repellence management options can help confirm which strategies are likely to be successful and profitable on particular soils and landscapes. The use of winged paired-row systems, winged points, banded-wetting agents, on-row seeding or broadcast spreading a proportion of the seed ahead of the bar can all potentially improve the effectiveness of sowing on water repellent soils and this is the subject of ongoing research.

• The Whole Farm Soil Mapping Project addresses the Caring for our Country and the South West Regional Natural Resource Management Strategy (2012 - 2020) targets to reduce the fertilizer and nutrient run off in to water ways through implementation of best practice fertilizer management on farms, as recommended in the Peel - Harvey Water Quality Improvement Plans (WQIP).

• In the dry season of 2001, lentils, field peas and canola yielded poorly whereas whet and barley yielded well.
• Hostile subsoil conditions limited the rooting depth of pulses and canola, while wheat and barley were more tolerant and able to extract moisture down to a dep of 1m.
• Pulses and canola will always struggle to perform in dry springs unless they are grown on soils where their roots can extrac soil water deeper than 50cm.

• The only way to accurately know your soil pH is to send a sample for a laboratory test (soil testing kits are available from the PIRSA Office in Kingscote).
• Have a look at the on-line acidity tools . They are easy to use and extremely helpful in guiding liming decisions.
• Liming will pay for itself, often in the first year. 
   

• The main difference in yield may have been due to poor tillage in the 500mm spaced crop.
• The entire crop was reliant on the soil nutrition from the pasutre as no fertiliser was applied to the paddock prior to and following seeding.
• Later sowing of the trial may have jeopardised the wide row's yield capacity therefore it would be encouraged that when considering sowing in wide rows early seeding is preferable.
• It may be noted that if nutrition was not a limiting factor for the 500mm crop, the water supply from the wide row may have increased yield to similar or better than that of the 250mm crop.

The results, even after relatively good spring rains, support the idea of conserving soil moisture between wide rows and reducing drought effects.

Stubble height can have a significant impact on wind speed close to the soil surface. This can increase soil erosion in vunerable environments (sand hills).

1. Winter cover crops can improve ground cover, increase plant available water and improve subsequent cotton yields in pivot-irrigated systems.
2. The early spray-out treatment was the best cover crop for storing water over the short fallow in this study where cover did not have to last very long. However, the extra cover in the mid-terminated cover treatment continued to boost infiltration in the cotton’s
early growth stages.
3. All cover crop treatments improved the yields of cotton by approximately 3 bales/ha; well in excess of any gains expected from the increased fallow soil water storage.

• Scout and Mace continue to out-yield the rest of the pack at Witera.
• Oxford and Fathom (WI4483) break 3 t/ha under severe leaf rust pressure at Witera.
• Espada and Scout top Elliston yields in 2011.

Take Home Messages

• Near perfect growing season for canola, provided ideal opportunity to assess the residual N feeding effect of the legumes.

• All legumes sown in 2016 – peas, lupins, sub clover and faba beans had similar starting soil N levels and soil water nitrate readings throughout the year which was reflected in similar grain yields inferring that all legume species were equal in terms of their N fixing capabilities.

• The average amount of N fixed by the legumes was calculated as ~86kg/ha.

• Growing adequately nodulated legumes can give rise to a ~1t/ha canola yield advantage compared with a non-legume.

• Linseed used more moisture, from a greater depth, than the faba beans in 2016. Resultantly more moisture was extracted by the canola crop sown on the faba bean stubble in 2017, and yet there is still more  residual moisture left.

• Pasture cropping systems can provide grain (and out of season fodder) on deep sandy soils and reduce the likelihood of groundwater recharge.
• Potential yield penalties associated with pasture cropping across perennials on deep sandy soils in the west midlands appear to be less than 20%.
• Pastures started competing with the crop for soil water during grain filling, but impacts on soil water and grain yield were generally small given average rainfall in spring.
• During the crop growing season, there was little difference in soil water under annual crop, perennial pasture, and pasture-cropped plots.
• Soil water contents were much lower under pasture and pasture-cropped plots during summer and autumn.

• Yield Prophet® in 2005 had many new features and capabilities and was delivered to 338 paddocks that were subscribed Australia-wide. From 5 April to 1 December, 6813 reports of various types were generated by subscribers, with most around time of top-dressing.
• Final simulated yields for wheat crops, using appropriately measured soil characterisation and initial soil data, fitted observed yields comparable to previous seasons (R2=0.74, 67% of simulated yields within 0.5 t/ha of observed, 98 % within 1.0 t/ha).
• Yield Prophet simulates yield more accurately than it does grain protein content.
• However, overall accuracy for all subscribed crops was lower due to expansion into new regions with less soil characterisation data available.

• APSIM simulations, accessed through the Yield Prophet web interface, were evaluated for their ability to forecast nitrogen fertiliser responses at the canopy management trial in the Wimmera.
• Yield Prophet accurately simulated crop yield and protein for a range of nitrogen fertiliser application rates and timings.
• Yield Prophet was able to estimate likely nitrogen fertiliser responses and dollar returns during the season.
• For accurate simulations Yield Prophet requires good soil characterisation data (crop lower limit, drained upper limit and bulk density) and pre-sowing measurements of soil water and available nitrogen.

The model was very accurate at the actual soil site location. Inaccuracies can be due to a number of reasons - namely weed burden at the site, frost, variations of soil type across the paddock and variations of rainfall received in the paddock versus the recording location. Furthermore, if the soil classification is slightly different in the model than is actually the soil physical properties, this could cause deviation as well. Lastly, as crop phenology can vary from cultivar to cultivar, this can cause discrepancy too.

Subsurface soil compaction has been shown to be a major constraint to crop production and the removal of
this compaction via deep ripping can lead to large yield increases.

Subsurface soil compaction has been shown to be a major constraint to crop production and the removal of
this compaction via deep ripping can lead to large yield increases.

• Removing soil compaction increased barley yield by between 710kg/ha and 1,130kg/ha in 2016.
• Very deep ripping (1200mm) gave the greatest yield increases at this site though there are factors that may inhibit the ability to rip this deep on a large scale.

• Statistical analysis was not possible on the trial, but the wheat following spray fallow treatment was by far the most profitable over the two years as well as the least risky.
• If this trial were to be repeated results will vary given different seasons and different soil types.

• Repellence can be worse below 5cm (5-10cm samples collected but not tested yet).
• If repellence is worse at 5-10cm this may explain why deep ripping has increased repellence as ripping could bring some of this more water repellent soil to the surface.

The Carlshausen’s had previously grown Calingiri noodle wheat but abandoned the variety in 2015 due to bad lodging in the 2014 season and consistent 0.1 t/ha lower yields than Mace. In 2015 they wanted to see if the new noodle variety Zen was able to match Mace (the only wheat currently grown on their property) in terms of yield and quality. Mace is a short to mid maturity Australian hard wheat with Wyalkatchem major parent and Stylet minor parent. Zen is a mid to long maturity Australian noodle wheat bred from Calingiri and Wyalkatchem.

Mace and Zen were compared in two locations of the same paddock. The soil type was similar at the two locations, but varied in their elevation.

This demonstration was conducted using farmer equipment. Farm scale demonstrations are a valuable way to explore new varieties, products, or practices, complimenting results which are produced through more scientifically rigorous, small plot trials. Please refer to NVT for a replicated view of the varieties in your area.

• The application of zinc had no effect on yield or grain protein.
• Zinc coated products are effective in supplying zinc.