To compare an opportunistic break crop against fallow and wheat to better define the pros and cons of fallowing.

• The moisture results indicate that canola uses more water at a greater depth than wheat. There is less water remaining in the soil profile below 40cm under canola sown at 1 and 6 kg/ha than for the same depth under wheat. There will be less moisture accessible to a wheat crop in 2012 on the canola plots than on the fallow plots.
• The use of fallow for moisture storage alone is unlikely given the volume of stored soil moisture at the beginning of May 2011. Indications for the use of a break crop were positive from early April. Summer rainfall had refilled the soil profile, fol-lowing the wheat of 2010, giving some surety to crop yield. Only a small rainfall event was required to break the season and join the soil moisture fronts.
• Season length and consistent rainfall has favoured yield of canola regardless of its plant density. A very plastic species as the yield from 22 plants/m2 is only 200 kg/ha less than that from 68 plants/m2. The canola plots received all required inputs as a result was a more expensive crop to grow than either the wheat or fallow.