• Reducing stubble loads can reduce the severity and duration of frost events under certain conditions. However, under the situation of multiple and severe frost events the influence of stubble is less defined and stubble reduction does not reduce risk.
• In the Mallee, most stubble management practices carried out prior to seeding to increase stubble incorporation or breakdown (cultivation, slashing) did not reduce stubble loads enough to reduce frost severity and duration.
• In the Wimmera, reducing stubble loads did not consistently reduce frost severity or duration possibly due to a combined effect of greater canopy closure with higher yield potential (2014) and higher stubble break down with low stubble levels (2015).
• Stubble management in frost prone areas is not about complete removal of stubble, but reducing it to a level that minimises your risk.

• Rainfall over the summer fallow period will cause nutrient leaching from stubbles.
• Stubble crop type determines initial value of stubble and what may be leached due to rainfall.
• It is important to consider other loss pathways such as microbial breakdown and volatilisation as well as leaching when calculating stubble nutrient value following the summer fallow period.

• Rainfall over the summer fallow period will cause nutrient leaching from stubbles.
• Stubble crop type determines initial value of stubble and what may be leached due to rainfall.
• It is important to consider other loss pathways such as microbial breakdown and volatilisation as well as leaching when calculating stubble nutrient value following the summer fallow period.

• In 2016, a Decile 10 season, stubble load had no effect on soil mineral nitrogen or soil water.
• The presence of stubble resulted in higher soil mineral nitrogen over the summer fallow period.
• Wheat yields were higher following peas or fallow than they were after wheat or canola in 2016.

• Treatment 1, Nil grazed, moderate stubble yielded the highest, (2.18 t/ha).
• No significant difference in Total Plant Available Water, majority of stored water was below the 50 cm depth.
• There was a significant difference between the eight treatments when comparing available soil nitrogen.
• There was a significant difference in grain quality attributes between the eight stubble treatments.

Stubble direction and height (plus or minus stubble) had no effect on crop establishment or grain yield for Blitz and Ace lentils

Preliminary results have shown that the removal of stubble can reduce frost severity and duration. However, this does not advocate the complete removal of all stubble on farming properties. The removal of stubble may be beneficial in low lying frost prone areas of paddocks.

Temperature results from both sites have demonstrated that stubble loads above 2t/ha increased the severity and duration of some frost events. Analysis of results on yield and frost damage is ongoing and will be presented.

Temperature results from both sites have demonstrated that stubble loads above 2t/ha increased the severity and duration of some frost events. Analysis of results on yield and frost damage is ongoing and will be presented.

Preliminary results have shown that the removal of stubble can reduce frost severity and duration. However, this does not advocate the complete removal of all stubble on farming properties. The removal of stubble may be beneficial in low lying frost prone areas of paddocks.

Adding 70 kgN/ha prior to stubble incorporation addressed in crop N tie-up.

Stubble direction had no effect on grain yield or quality for Mace wheat or Commander barley. Annual ryegrass counts were the same in rows sown North-South and East-West

High stubble loads appear to increase frost damage by reducing the amount of heat radiated from the soil at night, leading to lower canopy temperatures and greater frost severity, duration and damage.

• Rainfall over the summer fallow period will cause nutrient leaching from stubbles.
• Stubble crop type determines initial value of stubble and what may be leached due to rainfall.
• It is important to consider other loss pathways such as microbial breakdown and volatilisation as well as leaching when calculating stubble nutrient value following the summer fallow period.

• Rainfall over the summer fallow period will cause nutrient leaching from stubbles.
• Stubble crop type determines initial value of stubble and what may be leached due to rainfall.
• It is important to consider other loss pathways such as microbial breakdown and volatilisation as well as leaching when calculating stubble nutrient value following the summer fallow period.

• For different 2013 treatments, the amount of stubble ranged from 2.4 to 4.0 t DM/ha at harvest and from 1.6 to 3.0 t DM/ha at the subsequent sowing. The only statistically significant effect of 2013 treatments on 2014 pre sowing stubble was a difference between wheat and vetch stubble, 2.7 t DM/ha and 2.0 t DM/ha, respectively, reflecting faster breakdown of vetch than wheat stubble.
• Despite significant differences in the amount and types of stubble generated in 2013, and remaining at sowing in 2014, there was no statistically significant effect of 2013 treatments on 2014 soil moisture at sowing or 2014 crop yields.
• There were significant differences between crop types in 2014. Significantly more wheat plants established than canola (49 and 15 plants/m2 respectively) and wheat had a significantly higher grain yield than canola (1.2 and 0.3 t/ha respectively). Both wheat and canola were affected by the dry spring and associated frosts, plus canola had poor establishment.
• Research conducted previously at Walpeup in the 1980s found that maintaining 2 t/ha stubble increased the amount of water stored in the soil at sowing, at depth 0–140 cm, by 16 mm in 1 year of 3. This increase in soil water availability was not reflected in increased crop yield.
• The recent experiment at Ouyen, together with the previous research at Walpeup, indicate that Mallee crop yields are unlikely to be increased by retaining higher levels of stubble, although there can be benefits of reduced soil erosion.

• Different methods of stubble handling had little impact on yield.
• Early soil testing allowed good decision making for crop nutrition and budgeting.
• Soil biota were more active in the in-row root zone, as opposed to the mid row zone.

• Since soil moisture was not limiting, and a soft finish to the season was observed, sowing date trials at Minnipa in 2010 showed no differences in yield between stubble treatments under these conditions.
• This trial will be repeated in the same environment to validate across seasons.

• In 2007, herbicides applied to burnt stubble were more effective than those applied to slashed stubble. In 2008, there was no effect of stubble management on efficacy or crop safety.
• All herbicide treatments gave adequate control ofryegrassin both years, but TriflurX® 1.5L/ha + Avadex Xtra® 1.6L/ha gave the best control in both 2007 and 2008.
• Improved control of ryegrass did not increase yield, and the most profitable treatments were the lower rates of trifluralin.
• Standing stubble substantially increased grain yield relative to slashed stubble (0.41 and 0.47t/ha in 2007 and 2008 respectively).

• The combination of stubble burning and post-emergent use of a Group A herbicide has effectively controlled ryegrass in plots continuously cropped for 21 years at Condobolin.
• This combination worked well in both cultivated and direct drilled systems.

• Cereal stubble should be burnt when sowing wheat, barley or canola.
• The smaller the cereal and canola seedlings do not thrive when grown in stubble.
• Larger seeded crops such as chickpeas and lupins performed best in stubble retained situations.

• In wet years, barley sown into cereal stubble can suffer badly from yellow leaf spot.
• In dry years, this is not a problem.
• However, the barley still performed better where the wheat stubble has been burnt.

Crop stubbles provide a valuable feed source for stock over the summer period. The results from this trial indicate that grazing stubbles does not reduce either the amount of soil water stored during the summer fallow period or subsequent crop yield. In low rainfall environments, it is rarely possible to grow sufficient stubble to improve summer fallow efficiency by reducing evaporation (>5t/ha): growers should make use of this valuable feed source. Growers should maintain at least 70 per cent stubble cover (about 2t/ha of cereal stubble) to minimise the risk of wind erosion.

Crop stubbles provide a valuable feed source for stock over the summer period. The results from this trial indicate that grazing stubbles does not reduce either the amount of soil water stored during the summer fallow period or subsequent crop yield. In low rainfall environments, it is rarely possible to grow sufficient stubble to improve summer fallow efficiency by reducing evaporation (>5t/ha): growers should make use of this valuable feed source. Growers should maintain at least 70 per cent stubble cover (about 2t/ha of cereal stubble) to minimise the risk of wind erosion.

• With heavy stubble loads as a result of the 2016 harvest (11t/ha) burning significantly increased second wheat DM production throughout the season and gave a 0.7t/ha yield increase over the NTSR control treatments.
• This is the first year there has been a significant yield advantage with burning. In previous years, with stubble loads of 4–8t/ha, the yield gains have been non-significant or negative (as was the case in 2015).
• The yield response to burning over the four years averaged 6% (range -6% to +20%) compared with NTSR — long stubble.
• With a higher yield potential in 2016, applying nitrogen at sowing significantly increased grain yield and protein when stubble was cultivated, but cultivation has shown no advantage at this research site unless more nitrogen was applied.
• Over the four years the average yield increase from additional nitrogen has been 6% with adding 40kg N/ha to cultivated wheat straw and 3% from adding it to standing straw in NTSR, potentially indicating more nitrogen tie up with chopped wheat stubble when it was incorporated compared with standing stubble.
• The small differential effects of stubble management in year one (time replicates 1 & 2) have not resulted in follow-on effects in commercial crops sown in the following two years at this focus farm.
• Across this project, none of the tested fungicide treatments came close to replicating the level of YLS control achieved by burning stubble.

The 2017 season was significantly colder than average with about 500 hours below zero.

While stubble management may influence in-canopy temperatures, the differences between management practices were minimal during 2017.

Differences in frost damage of grains were significant between treatments at both the Coreen and Yarrawonga sites, with the burnt treatment showing the greatest frost damage at Coreen, while the no-till stubble retained (NTSR) treatments showed the greatest damage at Yarrawonga.

Stubble management per se did not influence frost damage in wheat during 2017, with frost damage not necessarily related to in-canopy temperatures.

Stubble management practices can influence the rate of crop development and may lead to changes in flowering time. This change in rate of development can influence crop susceptibility to frost at different times throughout the growing season.

 

Despite differences in DM production early in the season, there were no differences in yield or grainprotein due to stubble management treatments (burning, removing straw, cultivating or NTSR).
• There was a non-significant trend for burning to produce small yield gains (4–5%) over NTSR, a result seemingly linked to higher DM production.
• With a higher yield potential for 2016, applying nitrogen at sowing significantly increased grain yield and protein when stubble was cultivated. However this may be due to optimal nitrogen management rather than stubble management.
• In all three seasons of trials (2014–16), there was more DM accumulation earlier in the season and small non-significant yield gains (3–5%) when stubbles were burnt; however with a sharp finish to the 2015 season, burning significantly reduced yield compared with NTSR (12.5% yield decrease).
• Stubble management options that support high DM production earlier in the season (i.e. stubble removal) can be beneficial when yield potential is higher (2014 and 2016) and either neutral or disadvantageous in seasons when yield potential is lower (2015).
 

• Retaining short stubble with no-till full stubble retention (NTSR - short stubble) resulted in significantly higher wheat yields than where stubble was burnt, cultivated with extra nitrogen or straw removed.
• No-till full stubble retention with long stubble, and to a lesser extnet NTSR short stubble, gave better green leaf retention than other stubble management treatments; a result that may be linked to slower development earlier in the season.
• The stubble treatments set up during the 2014 season (burning, cultivating, removing straw) had no impact on the yield of the following barley crop compared with the NTSR control, although removing straw druing 2014 produced significantly superior barley crops in 2015 compared with cultivating the straw.

• Trial results were highly variable, with no significant differences in canola yield although there was a trend for the cultivation treatments to be higher yielding.
• Canola 650TT showed higher DM accumulation at flowering where the seedbed had been cultivated (multidisc) compared with the NTSR control, although adding nitrogen to the NTSR treatment negated this effect.
• The 2016 results were similar to 2014 when cultivation before sowing significantly increased canola yields.

• A highly variable trial with no significant differences in monola dry matter (DM) accumulation, nitrogen uptake or yields due to subble management.
• The 2014 cultivation treatments carried out before sowing the canola crop during the first year of the project significantly increased the yield of the following oat crop established using no-till stubble retention (NTSR).
• The yield increase in the following oat crops was reflected in significantly more biomass accumulation by the flag leaf.

• The addition of extra nutrients and stubble management (removed, incorporated or intact) did not affect grain yield or soil carbon stocks after three years of trial work.

• Under moist mid-April sowing conditions, there was a significant yield advantage (0.45t/ha) with one shallow-pass cultivation before establishing canola, compared with crops sown directly into standing wheat stubble.
• The yield advantage of canola following cultivation correlated to crops with higher vigour, early dry matter (DM) and greater nitrogen uptake.
• There was no significant benefit to mulching the first wheat stubble before direct drilling canola.
• The additon of 40kg N/ha at sowing gave a significant yield increase to crops established directly into the first wheat stubble, but there was no significant advantage to the additional nitrogen where stubbles were cultivated or mulched.

• Later-sown second wheat (20 May cv Young) established using no-till full stubble retention (NTSR) showed less dry matter (DM) production and nitrogen uptake during stem elongation compared with crops where stubble was burnt, cultivated or removed
• Although there was no statistical differences in yield, NTSR crops were the lowest yielding in a trial where yields ranged from 4.18 to 4.54t/ha.
• Burning significantly reduced yellow leaf spot (YLS) infection and decreased volunteer wheat populations before sowing compared with NTSR and cultivation treatments.
• NTSR crops had significantly lower test weights and higher screenings than crops established after stubble removal, burning or cultivation.

• The addition of extra nutrients did not increase yield, therefore it is expected that more nitrogen, phosphorus and sulphur remained in soil to breakdown stubble.
• Tillage practices (removed, worked or standing) also have no effect on grain yield or quality in both years of trials.

• The addition of extra nutrients did not increase yield, therefore it is expected that more nitrogen, phosphorus and sulphur remained in soil to breakdown stubble.
• Tillage practices (removed, worked or standing) also have no effect on grain yield or quality in both years of trials.

• A growing season rainfall (GSR) of 281mm resulted in average canola yields of 3.76t/ha.
• Reducing stubble length in NTSR, burning and removing wheat straw treatments significantly
• increased canola DM production at the greenbud stage (GS3.3) compared with NTSR — long stubble, despite there being no differences in plant establishment due to stubble management. 
• The significant reduction in DM in NTSR — long stubble was associated with a delay in the onset of flowering, which was statistically significant.
• The delay in crop development associated with longer stubble length was also observed in wheat at this site during 2015.
• Though there was a trend for the burnt and straw removed treatments to increase DM production compared with NTSR — long stubble, there was no difference in yield among any of the treatments at harvest.
• Across the four years of the trial 2014–17, NTSR — long stubble has reduced early DM production in all four years, however it has only significantly reduced final grain yield during 2014 (0.7t/ha decrease).
• The significant wheat yield reduction in 2014, due to long stubble, resulted in a significant increase in canola yields during 2015.
• The influence of stubble management treatments set up in 2015 (time replicate 2) did not affect the yield of the two subsequent commercial crops; canola in 2016, wheat in 2017.

A growing season rainfall of 509mm resulted in average yields of 5.8t/ha compared with 2.4t/ha in 2015 and 5.5t/ha in 2014 for the equivalent trial in a second wheat rotation position.
• Transient waterlogging influenced the results of the trial and gave variable yield effects resulting in a high LSD of 1.02t/ha.
• As a consequence, there were no yield differences during 2016 due to stubble management, with all treatments achieving 5–6t/ha yields, screenings less than 1% and grain protein levels above 10.5%.
• Though there was a trend for the burnt and straw removed treatments to increase plant establishment and early DM production compared with NTSR — long stubble (control), the trend for these treatments to be higher yielding (3–7%) was not statistically significant.
• Across the three years of the trial, NTSR — long stubble has reduced early DM production in all years, however it has only significantly reduced yield compared with other stubble treatments during 2014 (0.7t/ha decrease).
• The significant yield reduction in 2014, due to long stubble, resulted in a significant increase in canola yields during 2015.
• However, the influence of stubble management treatments set up in 2014 had no effect on the yield of wheat in 2016, following canola.

• Heat and moisture stress during spring resulted in average yields of 2.4t/ha compared with 5.5t/ha for the equivalent trial and rotation position duirng 2014.
• There were no significant differences in the 2015 yields due to stubble management, all stubble treatments resulted in low yields, high screenings and high protein levels.
• There were visual differences in green leaf retention due to stubble management and evidecne of slightly delayed maturity in the no-till stubble retention (NTSR) treatments.
• Although the NTSR - long stubble treatment decreased yields during 2014, this effect was not seen under the more stressful conditions of 2015.
• Canola sown during 2015 across the 2014 site yielded significantly higher in the 1024 long stubble treatment, presumably due to either water or nitrogen saving.

• Different active stubble management treatments producted second-wheat yields ranging from 4.98 to 5.85t/ha cv Corack.
• Stubble lenght of the pervious crop had a significant effect on yield when adopting no-till stubble retention (NTSR). Long stubble significantly decreased yield by 0.7t/ha in second-wheat crops compared with those established in short stubble.
• This yield reduction was associated with significantly lower dry matter (DM) production and nitrogen uptake in the stem elongation phase of crop growth.
• NTSR crops grown on short stubble also showed significantly lower DM production compared with crops following burning, straw removal and cultivation (two passes), but the reduction was less pronounced and did not reduce yield.

• There were no significant differences in lentil grain yield among seeding system or stubble treatments.
• Stripper and conventional stubble treatments resulted in taller and more erect plants with higher pods, improving harvestability