Lauren Celenza and David Minkey, WANTFA
There’s no doubt that no-till has brought WA growers fantastic benefits over the past three decades, including efficiency, moisture retention and soil structure. Before no-till took off in the 1990s farmers had to wait until rain to plough up and then sow crops, they knew from experience that if they ploughed up dry, sandy topsoils would blow and cause widespread degradation. Successful farm trials in the late 80s with one pass seeding using tines and discs lead to some early adoption in 1990. News was spreading of how well it worked, and not long after was the formation of WANTFA in 1992. The growers and researchers who formed WANTFA helped influence the rapid adoption of the system in WA over the next decade, until around 95 per cent of the States growers were no-tillers. But with the many benefits of no-till came some compromises and, particularly in the past ten years’ farmers have been somewhat reluctantly needing to till again. Herbicide resistance, compaction, non-wetting topsoils and stubble-born disease issues are increasingly becoming a problem. A no-till system with compact, acidic or non-wetting soil is not a sustainable no-till system. No-till was formed from a need to protect and build soil health, and now we have a need to fix the constraints compounded by it, but is tillage the answer?
In comes, strategic tillage. To WANTFA, tillage is ‘strategic’ if it’s going to alleviate a constraint and therefore help set up the soil for a successful and profitable (long-term) no-till crop afterwards. It can be seen as beneficial if it aids in things like soil compaction, non-wetting, acidity and herbicide resistant weeds and leads to a robust, healthy crop and abundant soil cover in the following years. What WANTFA wants to achieve now, is to help farmers chose which method, if any, is the best for them, and to ensure they have the right advice on pre and post tillage management to minimise any soil degradation that could occur. For some farmers, the thought of going back to tillage is a frightening one, and it’s important to highlight that there could be others ways of alleviating a constraint before factoring in tillage.
Compaction is becoming a huge issue in many no-till systems today. No-till farming, without tramlines, can create a compaction problem worse than any issues arising from a tilled field. By driving over the paddock without tillage the seeding, spraying and harvesting machinery all create compaction. Also, while some soils can soften themselves up with reduced traffic, most sands cannot. WANTFA, therefore, supports the idea of a strategic tillage followed by the adoption of a tramline system – otherwise we are just re-compacting the soils over time which is not a conservation farming system.
On the 30th of August 2016 WANTFA will be holding a Deep Ripper Demonstration day. Several manufacturers’ as well as local growers will be showcasing their deep rippers in a field demonstration, followed by discussions with researchers and industry on the merits of each machine, deep placement of lime to alleviate sub soil acidity, compaction and the benefits of ripping and tramline farming (See www.wantfa.com.au/news-events/ for more info).
Bligh, K., 2012, A brief history of establishing no-till sowing in Western Australia’, New Frontiers in Agriculture, WANTFA Journal vol. 20, no.2 pp. 46-47.
GRDC Strategic Tillage Fact Sheet, July 2014. Is there room for strategic tillage in a no-till system? Retrieved from https://grdc.com.au/Resources/Factsheets/2014/07/Strategic-tillage