• Despite visual differences there is no major impact on soil structure, water holding capacity or water infiltration from grazing in summer or winter when soils are water logged.
• Grazing in the previous winter or summer does not affect the following crop establishment or grain yield.
• Any yield losses after winter grazing are the result of moisture stress in the period immediately after grazing through to flowering.
• Annual ryegrass and wild raddish populations did not increase because of grazing, although the sites only had low levels of infestation to being with. However, farmer observations do not support this and further work is needed.

• Overall imposing a fallow allowed for a small amount of extra water to be stored in the soil and a small amount of extra nitrogen. As a result there was a small yield gain of 0.2 t/ha in 2012. 
• In this trial the fallow treatment was planted then sprayed out in August to replicate what is known as an ‘opportunistic’ fallow compared to a ‘strategic’ fallow where no crop is planted for 18 months. 18 month fallows would have different results to the ones reported here.
• Other benefits of fallow that were not recorded in this trial but could have contributed to the yield gain are improved weed control, disease breaks and opportunity for early sowing. 

• Wheat dry matter production and total crop nitrogen was significantly lower in wider row spacing treatments.
• For the all the crops grain yield was significantly lower in the wider row spacing treatments.
• Treatments imposed to manipulate crop growth were unable to save more soil moisture for grain fill.

• Crop water use and soil analysis values were very similar between the sites comparing long term reduced tillage and stubble retention.
• Reduced tillage and stubble retention has significantly contributed to increasing organic carbon levels at these sites.
• The grain yields of wheat were greatest at the sites with higher water use efficiency for each location.

• Crop water use and soil analysis values were very similar between the sites comparing long term reduced tillage and stubble retention.
• Reduced tillage and stubble retention has significantly contributed to increasing organic carbon levels at these sites.
• The grain yields of wheat were greatest at the sites with higher water use efficiency for each location.

• Crop water use and soil analysis values were very similar between the sites comparing long term reduced tillage and stubble retention.
• Reduced tillage and stubble retention has significantly contributed to increasing organic carbon levels at these sites.
• The grain yields of wheat were greatest at the sites with higher water use efficiency for each location.

• Modest autumn grazing of no-till crop stubbles sometimes leads to small measurable increases in surface soil bulk density.
• In two seasons, on soils in the Mallee and Wimmera, modest autumn grazing of no-till crop stubbles had no measurable effect on crop yield, quality or weed seed burial.

Light to moderate grazing of sheep on no-till stubbles in autumn is unlikely to have detrimental impacts on crop growth in the following season.

  Key findings:

Yield in the presence of crown rot was generally barley > bread wheat > durum across both sowing times, but significant differences were evident between varieties.

• Barley, bread wheat and durum varieties differ in their extent of yield loss from crown rot and their actual yield and grain quality (screenings) in the presence of this disease.
• However, all varieties are susceptible to crown rot infection and will not significantly reduce inoculum levels for subsequent crops. Variety choice is not a sole solution to crown rot.

Conclusions

• Sowing date and variety maturity choice is a balance between frost risk and terminal heat stress in the northern grain region. Both can have a significant impact on grain yield. No frost damage was evident at this site in 2014 with either sowing time but terminal heat stress did occur which was more severe during grain filling with the second sowing time. A three week delay in sowing time resulted in an average 24% reduction in yield across the winter cereal entries.  Later sowing pushed grain-fill too far into hotter conditions. This can reduce yield by itself but if there is also an underlying issue with crown rot then delayed sowing significantly exacerbates the expression of this disease with negative impacts on both yield and grain quality.

  Varieties do differ in their extent of yield loss from crown rot and in their relative yield in the presence of high levels of infection, which is often referred to as tolerance. This is a function of a varieties level of partial resistance to infection but appears to also interact with its environmental adaptation and maturity relative to the timing of stress (moisture and heat) which exacerbates the expression of crown rot. Generally quicker maturing barley, durum and bread wheat entries were higher yielding in the presence of crown rot infection in this trial. This does not necessarily mean that these varieties have improved levels of resistance to crown rot infection but rather their quicker maturity allowed them to minimize stress during grain filling relative to longer season entries, reducing the expression of crown rot.

  If forced into planting a cereal crop in a high crown rot risk situation then some barley varieties may provide a yield advantage over bread wheat in that season, as long as early stress does not occur. Some of the newer bread wheat varieties do appear to be closing this gap to some extent. Barley tends to yield better in the presence of crown rot infection due to its earlier maturity relative to bread wheat, providing an escape mechanism which reduces its exposure to moisture stress during the critical grain filling stage. However, a key message is that this decision is only potentially maximising profit in the current season. Growing barley over bread wheat will not assist with the reduction of crown rot inoculum levels as barley is very susceptible to infection. Significant yield loss is still occurring in the best of the barley and bread wheat varieties in the presence of high crown rot infection. Variety selection can improve yield in the presence of crown rot, though all varieties still suffer yield loss, which can maximise profit in the current season but this will not reduce inoculum levels for subsequent crops. Winter cereal crop and variety choice is therefore not the sole solution to crown rot but rather just one element of an integrated management strategy to limit losses from this disease.

• Depending on seasonal influence, stored soil moisture, soil nutrition, stocking rate management and correct timing (early tillering at growth stage (GS) 18-22, rather than later tillering at GS 24-28), grazing can be done with no detriment to crop yield.
• However, preceding paddock history had a significant impact on subsequent crop success and needs to be considered when planning future rotations.

• Burning or cultivating 2015 stubbles tended to produce higher yields, however this was only significant at Ungarie.
• High rainfall and a soft finish removed the benefit of stored soil moisture that stubble retained systems may have provided.
• Nitrogen was the limiting factor for both yield and protein for 2016.
• Growers cannot let stubble negatively impact on weed control and timely sowing.
• Growers should use crop rotation to their advantage by aiming to sow the right crop into the least antagonistic stubble.
• Stubble retained systems can require more nitrogen due to increased nitrogen tie-up.

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

• Canola and peas only produced half the yield of wheat, but barley performed very well.
• Ryegrass is becoming a problem in wheat on wheat plots.
• Pastures performed well where seed reserves had been increased in 2011.
• All options had good soil moisture (40mm) at the start of the season.

The data would suggest that Deep Ripping had an effect on increasing the total water content of the soil, thereby making more moisture available to the barley crop during the spring months at a time when the crop was filling the grain. This may have resulted in a higher grain yield for both Ripped and Ripped + Gypsum treatments by comparison to the Direct Drilled and Shallow Cultivation treatments (although yield difference not statistically significant). 

For further conclusions please see the attached trial report.

Results from the Northern Agricultural Region have shown that crops can be sown over subtropical perennial grasses without jeopardizing persistence of the perennial base. However, perennial grasses vary in their tolerance to in-crop herbicides and crop yield is dependent on effective weed control, adequate fertility and moisture, and winter dormancy (or suppression) of the perennial pasture.

Pasture cropping systems can also lift overall biomass production, improve the feed value of stubbles, provide out of season fodder, and reduce the likelihood of wind erosion and groundwater recharge on deep sandy soils.

The application of additional nitrogen can lead to greater biomass in both the annual crop and perennial pasture. However, this is dependent on seasonal conditions and the economics of applying additional nitrogen needs to be considered carefully on low moisture holding, infertile, sandy soils in the Northern Agricultural Region.

• Conserving summer rain is one of the most effective ways of improving crop yield.
• Summer weeds have the biggest impact on how much summer rain is stored and made available to crops.
• The presence of stubble has never been shown to have a large positive effect on the storage of summer rain in southern Australia, but it might lengthen the sowing window after the break and improve establishment.

The application of compost at 2 t/ha did not result in higher returns and the response under compost plus fertiliser treatments could be attributed to the application of fertiliser. Spading did not return any further gains in terms of yield or quality at this site in 2013. The high cost of spading and compost in the first year, have negatively influenced profit outcomes. Depending on future yield improvements, these treatments may pay for themselves over the longer term.

No measureable changes in soil condition as a result of adding 2 t/ha compost were measured in 2013 and 2014 that would add value to the long term profit of this site.

Machinery used for applying compost caused some compaction and due to the dry post-sowing conditions, crop germination was very patchy. The trial site experienced significant moisture stress early in the season and may not be representative of seasons experiencing an average or wetter start.

• Wheat grain yield in 2007 was increased by 0.2t/ha after the addition of 5.0t/ha of wheat straw
• Straw is important for decreasing evaporation and conserving moisture in topsoil, particularly after canopy closure and when the crop is senescing
• The additional moisture available under straw significantly increased dry matter production after GS65.
• Inter-row sowing reduces straw burial

Neither crop establishment, grain yield nor quality were changed by on-row seeding or by increased seeding rate in 2017, similar to results in 2016.

Crop establishment in the non-wetting soil was poor in 2017.

In 2015, with low moisture at seeding, improved crop establishment from on-row seeding in the non-wetting soil increased crop competition and lowered brome grass weed seed set.

• Under the current dry conditions there is limited water in the subsoil which makes this project difficult.
• Soil sampling throughout the year on various paddocks showed plants using what little subsoil moisture was available.
• Since subsoils were not very wet, it is unlikely that the sodic nature of the subsoils was expressed.

• Seasonal conditions reduced the potential impacts of the pre-emergent herbicides evaluated in this trial with sowing taking place under dry conditions. The top 5 cm was dry with little follow up moisture although there was enough to get the crop out of the ground. The effects of pre-emergent herbicides are generally more pronounced under very moist conditions particularly under intense heavy rain events at seeding or when the top soil is saturated for an extended period at plant establishment.
• In this trial neither yield or weed density were significantly different between the herbicide treatments.
• Weed plant densities were extremely variable within each treatment so caution should be taken when comparing grass weed efficacy in this trial.

• There is still a lot of work to be done but it appears crops can be sown successfully into perennial pastures in some situations.
• Agronomic results from the Moora focus site appear to support the view that Marginal or problem soils are a potential fit for pasture cropping systems. However, it is important to note that the extra green feed produced over summer-autumn needs to be converted into wool or meat in order to offset any grain yield losses.
• Further research is required across different sites and seasons as the yield penalty on better soil classes may well be greater than on deep pale sands which have limited capacity to store moisture from summer rainfall for crop production. The viability of pasture cropping systems based on other sub tropical grass species, native grasses. lucerne and bluebush are also worth evaluating.

• 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.