Investment

Stubble retention practices in the Wimmera following recent high production years is leading to issues with canola establishment in subsequent years. Growers are utilising burning to manage these high stubble residue loads preventatively however this leads not only to loss of organic matter and nutrients (NPKS), and reduced water infiltration but also increases the risk of soil erosion. Where high stubble loads are retained, establishment is being impacted by stubble effects on seeding operations, affecting seed depth, shadowing of emerging seedlings retarding early growth/ vigour, chemical tie up and the harbouring of pests and diseases among other factors. Growers are interested in understanding what the optimal stubble load is that can balance these risks and what tools can be used to manage stubbles to the optimal load after big production years. The other component to this issue relates to when optimal establishment is not achieved (reduced density [<5plants/m2], staggered germination), where growers are unsure about the point at which to cut their losses and resow with a different crop.

This investment is a two year trial program, designed to help growers objectively assess the level of stubble they have in their paddocks and to identify and implement practices to achieve optimal establishment of canola using a range of common seeding systems without burning practices.