No till proved worth in difficult 2000
GroundCover™ Issue: 35
Driven by the erosion loss of a farmer's most valuable resource, soil, a small group of WA graingrowers began 10 years ago to discard tillage in favour of a one-pass operation using narrow points to minimise soil disturbance.
They have since been joined by hundreds of others, all of whom now passionately push the merits of a whole-farm systems approach, encompassing all aspects of farm management that help them achieve the desired outcome of maximising crop yield, while minimising soil damage.
WA No-Tillage Farmers Association (WANTEA) immediate past president, Geoffrey Marshall, has practised no-tillage at his 3,000-hectare Hyden farm since 1994, two years after WANTFA started.
"The group was driven initially by erosion problems along the south coast, with farmers there seeing the value in not cultivating and getting seed in without turning the soil over.
"WANTFA now advocates a double knock at seeding, with sprayseed following glyphosate, a combination which, importantly, will also help hold off the development of weed resistance to glyphosate.
He said a whole-farm systems approach is developing to manage weeds, make best use of crop residues and select crop types and varieties for their suitability to a no-tillage system.
"Surface stubble retention is important in a no-tillage system, as ploughing stubble back in, as some advocate, disturbs the delicate balance of bacteria, which will still do their job without stubble being ploughed in, provided there's enough soil moisture.
"Stubble residues are also a huge tool for suppressing weed germination. This, combined with high seeding rates and reduced tillage, will help suppress weeds."
Get rotation, right to suppress disease
"With reduced cultivation, you must get the rotation right to lower disease carryover and this is where new phase farming systems, using lucerne, may have a good fit.
"Last year was a classic no-tillage year, with those who set up right by having good rotations, early weed control, no-tillage and stubble retention able to seed early and take advantage of existing soil moisture."
A case in point is Jerramungup farmer Rex Parsons who started practising minimum tillage in the early 1980s and has been refining machinery and methods since. He says that without no-tillage his yields in 2000, a very difficult year, would have been far less.
He saw it in side-by-side paddocks, with one scarified to control marshmallow. The non-worked paddock yielded 1.1 t/ha and the worked 0.6 t/ha.
Seven years of better results
Matthew Steber of Doodlakine says wheat yields climbed to an average of 1.94 t/ha over seven seasons of no-tillage, versus 1.64 t/ha for the seven seasons prior.
"In my farming operation, the package has also allowed me to take full advantage of an extended sowing window that would not have been possible under conventional sowing techniques, leading to many economies of scale.
"Given a reasonable timing of opening rains, a four-week sowing window is achievable where we farm, without incurring any significant time-of-sowing yield penalties," he said.
Mr Steber noted that this theoretically should allow a 5,000 ha cropping program to be completed by one sowing unit, compared to, say, 3,000 ha under a conventional sowing system. He calculates this as saving 33 per cent in the fixed costs of owning a large seeding unit.
Seeing the benefits in a hard year
Luke Sprigg of Bonnie Rock agreed that last season, with only 125 mm growing-season rainfall, reduced and no-tillage allowed paddocks, whether sown early or not, to establish reasonably and grow well. "But this was only the case if they had suitable preparation," he noted.
In his case this included six years of prior no-tillage system, prompt summer weed control, suitable stubble retention, ConservaPak furrow and long moisture-seeking opener.
Mr Sprigg said last year showed that complete no-tillage management could reduce risk and create profit.
He uses two Flexicoils, one on 12-inch row spaced ConservaPak, and the other on 7-inch row spaced DBS knife points, followed by a prickle chain.
"The ConservaPak does any heavy stubble, dry sowing and used to do all the moisture-seeking sowing.
"Now, with the more conventional bar having the longer DBS points, it's doing much of the moisture seeking and it provides as good, and sometimes better, germination," he said.
National Pulse Farmer of the Year, Neil Wandel, who farms about 9,000 ha on WA's south-east coast, benefits from stubble retention, no-till and careful nutrient management.
He has reported a 3 t/ha wheat crop sown with a Janke No-Till seeder and, despite receiving only 100 mm between May and October last year, he was amazed at how well the crop hung on.
According to WANTFA, this result is attributed to Mr Wandel's history of almost continuous stubble retention over the last nine years and careful nutrient management.
He started min-till in 1982 and moved to no-till in 1986 and, since that switch, has noticed dramatic changes to soil structure and crop yields.
Problems still being dealt with in min-till systems include preventing herbicide resistance, finding a better way to handle residues when sowing and soil acidity as well as, for some farmers, a continuing battie with weeds.
Region North, South, West