Plentiful rainfall in the Wimmera and most of the Mallee this growing season has resulted in crops producing an abundance of biomass, and growers are being urged to think about stubble management this harvest to avoid problems next year.
Issues, such as poor crop emergence and seeder blockages, can arise in paddocks where there is a large amount of crop residue, but according to research carried out through the GRDC stubble initiative, many problems can be avoided with adequate forethought and preparation.
BCG research manager Claire Browne, who is leading the stubble project in Victoria and Tasmania, said a successful retained stubble farming system begins at harvest.
“When planning harvest logistics consideration needs to be given to the type of stubble that needs to be produced and how crop residues will be managed for optimum outcomes the following season,” she said.
To avoid issues associated with stubble retention, such as seeder blockages, poor crop emergence and reduced herbicide efficacy, Ms Browne said stubble left standing in the paddock after harvest should be even and at the appropriate length (according to crop rotation and machinery capability) and chaff and straw should be spread evenly across the paddock.
The situation was similar following the 2010 harvest when bumper crops brought challenges not experienced during the dry decade that proceeded it.
Grain Producers Australia’s chairman and Rupanyup farmer Andrew Weidemann said farmers were drawing on these experiences to help prepare for harvest 2016.
“We’re now better at managing stubble loads than we were in the past,” he said.
“Each farmer has their own way of doing things that takes into consideration the issues on their property, crop rotations and machinery capabilities,” he said.
There are many challenges farmers face at harvest time in regards to stubble loads – harvest height, harvest speed, material throughput, residue spread, moisture content of residue, weather conditions and thinking about the best conditions for subsequent crop.
When considering the height at which a crop is going to be cut, timeliness and efficiency need to be taken into account.
Cutting higher will result in faster harvesting times, but stubble may need to be managed after harvest (eg grazing, baling, slashing or burning). Harvesting lower will result in shorter stubble height but will take longer and fuel consumption will be higher.
Mr Weidemann said on his farm getting the crop off in a timely manner was the priority so the header cutter bar would be set relatively high.
He said this may mean having to return to the paddock to manage stubble before sowing the 2017 crop, depending on the crop type being sown.
“If we are going to be planting more canola next year we will need to reduce stubble loads to reduce the effect of shading on seedlings,” he said.
“While if we are going to grow more pulses the need to reduce stubble height is not as necessary.”
Ms Browne said there was no one stubble management option that would suit every farm and every situation.
However, she said decisions and planning need to occur soon in preparation for what is shaping up to be a busy harvest.
“Start thinking, planning and discussing with advisors how best to handle large stubble loads on their property,” she said.
“Effective communication with contractors at this time is also paramount especially if you plan to vary your current methods.”
You can find more information about managing stubbles via the GRDC-funded ‘Stubble Project’ website at: www.thestubbleproject.wordpress.com/