Key Points

• Plant establishment numbers were strong across the site

• Weed control was adequate across the site

• There were significant differences in crop maturity and biomass between treatments.

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Aim

• Demonstrate that growing canola (with effective weed control options) followed by a high-value legume (with higher economic value) can lead to an effective and profitable double break crop sequence. The contribution of an early sowing date versus a traditional sowing date to increase the profitability of these crops will also be evaluated.

• Determine the economic value of growing canola followed by a high-value legume and the impact of this rotation on the grain yield and profitability of a cereal crop in the first year following the double break crop sequence.

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Background

While break crops have traditionally been used as a single crop in rotation, the use of two break crops in a sequence has been shown to greatly increase cereal crop production and profitability, particularly as shifts in disease presence and increases in herbicide resistance in weeds has reduced the effectiveness of a single break crop.

 

The most desired traits of a break crop are to be highly effective in controlling weeds and disease while also being highly profitable. Current highly effective break crop options of canola and lupin are rated as moderate to low profitability (respectively) by growers, while pasture phases or fallow period generally result in a low or negative Gross Margin. The integration of high-value legumes such as chickpea or lentils have been successful in medium to low rainfall environments of Eastern Australia to improve crop rotation profitability while maintaining effective weed control.

 

Recent studies in WA found that profitable grain yields of both chickpea and lentils are achievable in the medium rainfall zone (MRZ) of the WA Wheatbelt. The impact of earlier sowing of these pulses has also been demonstrated to significantly increase the profitability of these high-value legumes. The downside of high-value legumes is that potentially these break crop options have less developed (and therefore less effective) weed management packages for the WA environment.