GRDC stubble management guideline No. 2
One of the biggest challenges to operating in a stubble retained system is management of the crop residue present in the paddock at sowing time. Inability to effectively sow through retained stubble and subsequent seeder blockages can make initial adoption of stubble retention challenging.
In the early days of no-till adoption, a common way growers overcome these challenges was by widening the row spacings on their seeding machinery from the traditional 7” (18cm) or 9” (22.5cm) out to 12” (30.5cm), 15” (38cm) or even 30” (76cm).
As well as offering a means of successfully sowing into standing stubble and crop residue, wider row spacings meant sowing speeds could be increased, machinery maintenance, set-up costs and fuel costs were reduced, pre-emergent herbicide safety was improved and inter-row sowing was easier.
However, as retained stubble farming systems have evolved along with machinery improvements, including disc systems and better GPS guidance, many growers have questioned the value of wider rows with higher yields, better weed competition and less soil water evaporation key benefits of narrower row spacings (25cm or less).
More diverse crop rotations are also having an influence with certain break crops found to be better suited to certain row spacings. Cropping environment will also have a bearing, with specific guidelines relevant to growers in the low to medium and high rain zones, and the Murray Mallee irrigation region.
As part of the ‘maintaining profitable farming systems with retained stubble in Victoria and Tasmania’ project Birchip Cropping Group (BCG), Southern Farming Systems (SFS), Irrigated Cropping Council (ICC) the Victorian No-Till Farmers Association (VNTFA) have been investigating how row spacings influence crop production in retained stubble farming systems.
Findings from field trials and demonstrations carried out as part of this project as well as previous research and anecdotal evidence from leading farmers and consultants, has been considered in developing regionally specific guidelines for the Wimmera Mallee, the Murray Mallee irrigation region and Tasmania.
More information about choosing a row spacing for retained stubble systems can be found here.