• In a dry season, there was a small grain yield benefit (90kg/ha) for wheat that followed terminated vetch and field peas (1.5-2.4t/ha of biomass), compared with fallow and terminated medic.
• Soil water benefits from fallow and legume termination don’t occur with dry spring finishes.
• Using soil tests to measure nitrogen mineralisation helps you to properly evaluate the benefit of a legume crop or pasture in a rotation.

When sub-soil water is present, growing high value canola and legume break crops can be profitable in the Mallee.

Where brome grass seed bank populations are high, break crop sequences of longer than two years are necessary to decrease numbers, and keep them down.

The application of CLF herbicide chemistry is effective in reducing brome grass populations, but herbicide resistance will develop quickly if they are used repeatedly in the same paddock.

• Nitrous oxide losses following rainfall from a wheat crop sown into vetch stubble that was terminated in various ways in the previous year were low: ~ 1.5 g N/ha/day or less.

• Nitrous oxide (N2O) losses appear to be minimal from dry-land low to medium rainfall farming systems; with the highest peak emissions of only 4.0 g N2O-N/ha/day measured following rainfall.  
• N2O emissions from legume stubble over summer and following synthetic nitrogen fertiliser application in-crop were all low.  
• An increase in soil water was the major driver of N2O emissions.

• N2O losses appear to be minimal from dryland low to medium rainfall farming systems; peak emissions of only 4.0 gN2O-N/ha/day were measured following rainfall.
• N2O emissions from legume stubble over summer and with synthetic fertiliser applied in-crop were low.
• An increase in soil water was the major driver of N2O emissions.

• N2O losses appear to be minimal from dryland low to medium.
• Rainfall farming systems; peak emissions of only 4.0 g N2O-N/ha/day were measured following rainfall.
• N2O emissions from legume stubble over summer and with synthetic fertiliser applied in-crop were low.
• An increase in soil water was the major driver of N2O emissions.

When vetch is establised in March and is terminated 'early' (three to four months later, in June, July), soil water will be conserved for the subsequent wheat crop; the risk of haying off due to high nitrogen will be lower than if the vetch were terminated 'later' (August, September),

Vetch biomass production of approximately 2t/ha is unlikely to cause a subsequent wheat crop to hay off given dry seasonal conditions. 

Residual nitrogen from vetch brown manure can carry over for two years and influence cereal crop growth, but the conservation of soil water is more critical in seasons of Decile 2 or lower. 

When vetch is establised in March and is terminated 'early' (three to four months later, in June, July), soil water will be conserved for the subsequent wheat crop; the risk of haying off due to high nitrogen will be lower than if the vetch were terminated 'later' (August, September),

Vetch biomass production of approximately 2t/ha is unlikely to cause a subsequent wheat crop to hay off given dry seasonal conditions. 

Residual nitrogen from vetch brown manure can carry over for two years and influence cereal crop growth, but the conservation of soil water is more critical in seasons of Decile 2 or lower. 

When vetch is establised in March and is terminated 'early' (three to four months later, in June, July), soil water will be conserved for the subsequent wheat crop; the risk of haying off due to high nitrogen will be lower than if the vetch were terminated 'later' (August, September),

Vetch biomass production of approximately 2t/ha is unlikely to cause a subsequent wheat crop to hay off given dry seasonal conditions. 

Residual nitrogen from vetch brown manure can carry over for two years and influence cereal crop growth, but the conservation of soil water is more critical in seasons of Decile 2 or lower. 

Early termination of vetch resulted in higher soil N and soil water at sowing the following year compared with later termination timings of vetch. Wheat yield in the year following vetch was highest for the earlier termination timings of the vetch. Brown manure vetch had higher soil N and soil water compared to vetch taken through to harvest.

In years with high summer rainfall, growing break crops is low risk and is an effective management strategy for reducing weeds, while growing profitability. Two year breaks are better than one at achieving favourable returns and reducing brome grass populations. The best brome grass control and gross margins were achieved by two year rotations of Clearfield canola/vetch and continuous Clearfield wheat followed by wheat.

Nitrous oxide losses from nitrogen fertiliser products compared in this trial were low: 1 g N/ha/day or less. Granular urea and granular urea plus inhibitor fertiliser provided the greatest yield benefit this season. Potential benefits from different fertiliser products will be realised if seasonal conditions and timing of plant growth are matched.

Topdressing pulses with nitrogen does not pay; inoculation does. Nitrogen topdressing of pulses resulted in little or no net growth or yield benefit. Inoculating pulses is most effective if the soil is moist and if residual soil nitrogen and soil rhizobia populations are low. The current study indicated that a return on investment of up to $60 can be achieved from the inoculation of chickpeas in the absence of soil rhizobia.

Early termination of vetch resulted in higher soil N and soil water at sowing the following year compared with later termination timings of vetch. Wheat yield in the year following vetch was highest for the earlier termination timings of the vetch. Brown manure vetch had higher soil N and soil water compared to vetch taken through to harvest.

• 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.

To manage N2O emissions in low to medium rainfall environments, growers need to match nitrogen supply to crop demand. Lowest emissions were measured where nitrogen levels were least, while highest emissions occurred where nitrogen levels were greatest. Applying late nitrogen to increase wheat protein is not economic when segregation price differentials are small.

Nitrogen (N) fixation by vetch was closely related to dry matter (DM) production (26kg N fixed per tonne DM accumulated). The later the termination, the higher the calculated inputs of fixed N. Both soil water reserves and mineral N were highest at the end of the 2012 growing season following the earliest (June and July) termination timings. To establish the best time to terminate a vetch crop, weigh up the benefits being delivered by vetch (biomass accumulation and N fixation), the need to conserve moisture and time required for N to mineralise for the next crop.

• Where blackleg disease pressure is low, fungicide application is not necessary.
• The greater the amount of canola grown, the more likely is an infestation of blackleg.
• Consequently, in 2012, blackleg disease pressure may increase in the Wimmera and Mallee.
• A buffer of 500m from the previous year’s canola stubble is desirable when selecting canola paddocks.
• Growers should utilise the “Blackleg Risk Assessor” and the current “Blackleg Ratings” on the GRDC website.

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.

As the climate is changing to warmer conditions and the atmosphere contains more CO2 (also called CO2 fertilisation), crops grow more quickly and mature earlier. It is important to be aware of these effects on crops so that the risk of frost or heat shock reducing crop yield can be better managed. Even though the climate is warming, it is not clear whether the occurrences of frosts are reducing. In fact, there is anecdotal evidence that frost severity and frequency are not changing, which could be because there is reduced moisture in the atmosphere. If this is the case, it will have implications for sowing time and variety choice. Through the use of PA and VR, growers are able to sow different varieties on more frost prone areas. Without this technology, growers would either need to sow different zones separately, reducing efficiencies, or treat the paddock as a whole, which may see reduce yields and risk in various zones. To demonstrate the advantages of this strategy, over the past two seasons, BCG and SPAA have undertaken paddock scale trials. Two demonstrations were undertaken to compare two varieties of different maturity at two different sowing times.

• Significant reductions in water and chemical use can be achieved when weed sensing technology (WeedSeeker) is used, compared with blanket applications.
• Erect plants compared with prostrate plants require less spray.