THERE was no-one wearing fluoro or shoulder pads but the key messages from last week’s Grains Research and Development Corporation (GRDC) update for advisors in Bendigo bore an uncanny resemblance to the 1980s.
Strategic tillage, narrow row spacings and even burning for weed, pest and stubble management were all raised as potential management strategies, coming after a decade where hard line no-till systems have been in vogue.
However, the speakers were at pains to highlight their advice did not mean a return to the days of working fallow three times before sowing, saying tools such as tillage or burning needed to be implemented sparingly to preserve soil structure.
“The simple point is that a strategic tilling can boost yield on certain soil types,” said outgoing research scientist with the NSW Department of Primary Industries (DPI) Mark Conyers.
“Limestone needs to be incorporated into the soil or else it does little to ameliorate acidity, while without tillage, nutrients can often gather very close to the surface where they are less accessible for plants,” Dr Conyers said.
However, he reiterated that farmers needed to know their soil types before cultivating.
“I think a strategic tillage program, provided it is only done once every four years or less frequently, can work on red and grey clay based soils.
“If you had self-mulching black clays that renovate themselves then it would not be necessary.”
Peter Newman, communications manager with the Australian Herbicide Resistance Initiative (AHRI), said trials had found narrow row spacings were working in terms of lowering weed numbers.
“An 11 year study has showed narrow row spacings reduce annual ryegrass seed production.”
The narrow row spacings improve the competitive advantage of the crop species and reduces the number of weeds.
Mr Newman recommended farmers combine this strategy with a post-harvest weed seed control, such as either the use of a harvest weed seed destructor or residue burning.
He said overall paddock burning was very effective in controlling ryegrass seed numbers, but cautioned it did lead to a dip in yield.
Instead, he said innovations such as chaff carts made it possible to burn piles of trash or farmers could gather trash in narrow windrows for burning.
Tony Swan, CSIRO, co-ordinator of a CSIRO project into retaining stubble, said farmers this year had to contend with heavy stubble loads due to the big yields in 2016.
He said there were a range of management strategies, such as mulching or grazing stubbles that could help farmers lower the stubble load.
However, he said for farmers with tined machines in particular, the stubble load may remain too heavy and he too raised the possibility of a strategic, one-off paddock burn.
“Getting through stubble is going to be a big issue leading into sowing in 2017 and it is important that farmers are proactive,” he said.