Simulations indicated that sowing opportunities in a suitable window (prior to May) occurred in 40% of years at Wagga Wagga. Vigorous cultivars established at adequate plant density (>60 plants.m-2) with plentiful nitrogen supply (200 kg.ha-1) provided grazing opportunities of 400-1000 DSE.days.ha-1 in June to mid-July, and could recover to achieve the target biomass of ~5000 kg.ha-1 at flowering on September 1 to avoid yield penalties. Flexibility to manage crop agronomy and livestock grazing according to the emerging seasonal conditions was demonstrated. For example, crops grazed heavily up to July could recover from 1200 kg.ha-1 residual biomass, while lightly grazed crops could have stock removed in early August provided 2900 kg.ha-1 biomass remained. Overall this work indicates significant opportunity for dual-purpose canola in the medium rainfall areas of south-eastern Australia and provides a framework for assessing the concept in other areas. These assessments could be improved with modifications to simulation models which better capture the physiology of crop recovery following grazing.
|Qualification||Doctor of Philosophy|
|Place of Publication||Australia|
|Publication status||Published - 2011|