One-pass technique for non-wetting soils
GroundCover™ Issue: 106 | Author: Melissa Williams
Two Western Australian grain producers are among the first in the country to use a one-pass mouldboard ploughing and seeding configuration to manage and sow their non-wetting soils.
Michael (Mic) Fels and David Cox farm near Esperance on WA’s south coast where water-repellent soils are a major constraint to crop establishment.
Mouldboard ploughing is one option being trialled as an amelioration tactic for overcoming the symptoms of non-wetting soil: poor water-holding capacity, water repellence and acidity.
Department of Agriculture and Food, WA (DAFWA) senior research officer David Hall says research is showing mouldboard ploughing can significantly boost yields, and the benefits so far are persisting for several seasons.
He says mouldboard ploughing re-engineers sandplain soils and, in one pass, can bring wettable soil to the surface, de-compact subsoils, bury weed seeds and – where subsoil acidity is an issue – allow lime to be incorporated at depth.
However, a limitation to its adoption on the southern coast is the risk of wind erosion on freshly exposed soil, which quickly dries, making it too crumbly for multiple machinery passes.
By modifying machinery to mouldboard plough and seed in one operation this season, Mic and David reduced the propensity of the soil to blow away and achieved good wheat and barley germination.
Mic and Marnie Fels
Mic and Marnie Fels estimate 25 per cent of their 6000 hectares of cropping land is non-wetting and requires mouldboard ploughing.
A successful trial on 10ha in 2011 prompted Mic to mouldboard plough 200ha in 2012 with a hired machine.
He says this cost about $85/ha, which required an increase in wheat yield of 0.3 tonnes/ha on that area to recoup the investment.
He picked up an extra 1t/ha in wheat yield and side benefits included a more uniform germination, which allowed more effective herbicide applications, and improved wild radish control through the weed seed being buried.
Mic says the main downside of mouldboard ploughing is that when the soil is turned over, it becomes powdery and fragile within a day if it is disturbed again. This increases the risk of wind erosion and makes it difficult – and potentially damaging – to pull seeding equipment through the soft soil.
After trialling various systems in 2012 and brainstorming ideas with David Cox, Mic sowed Mace wheat in 2013 on 600ha of deep sandplain soils with a one-pass ploughing and seeding system.
A 261-kilowatt tracked tractor was used to pull an eight-furrow John Deere 995 reversible mouldboard plough, which was then hitched to a modified Case IH combine mounted with coil packers.
“The soil was mouldboard ploughed to 40 centimetres, the seed broadcast on top with the combine and rolled in with the heavy coil packers,” Mic says.
“It was a bit crude, compared with the modern no-till systems we normally use, but it did the job, and in one pass, which was the key for me.”
For simplicity, Mic did not add any fertiliser at seeding. Trial strips in 2012, and other work he has seen, showed no phosphorus response in the first season of mouldboard ploughing.
He says there are difficulties going back over the treated area when it is in crop, but he plans to move to controlled-traffic farming to relieve compaction issues.
By late May, the one-pass, mouldboard ploughed and sown Mace wheat had germinated and established well.
Mic says the success of this system would make a big difference to Esperance-region growers.
“In the high-rainfall sandplain region, crops that get enough rainfall to yield 6t/ha are barely yielding 2t/ha. I’m hoping to fill some of that gap by fixing the non-wetting, compaction and deep fertility constraints in those soils. And there are the spin-off benefits of better weed control and less erosion.”
Mic aims to refine his machinery set-up for 2014 and beyond to create a more robust, reliable and simple configuration.
Ideally, he would like a small airseeder mounted to the front of the tractor to avoid having to pull a heavy machine.
David and Sally-Anne Cox
About 20km from the Fels’ property, David and Sally-Anne Cox undertook mouldboard ploughing for the first time this year, also using a one-pass seeding operation.
“We have fine sands that tend to blow and post-ploughing trafficability is very challenging,” David says.
“We know mouldboard ploughing will help overcome our non-wetting issues, but the package is all wrong for our soils. Seeding after mouldboard ploughing is difficult because the ground is too soft and wet for machinery, and if you delay seeding, the seedbed dries too fast.”
To overcome these hurdles and reap the benefits of mouldboard ploughing, David set up his own machinery configuration to sow 600ha of long-season Urambie grazing barley and 400ha of Mace wheat in 2013.
It comprised a 410kW tractor on dual wheels pulling a tow-between airseeder bin with three-point linkage (modified and strengthened), which towed a new 12-furrow Gregoire Besson reversible plough and a set of coil packers. An airseeder kit ran through the plough and onto the coil packers.
The ploughing depth was 30 to 35cm and seed was sprinkled on the surface and then packed to a depth of 0 to 3cm.
David says the result was excellent, achieving an even germination across paddocks that ranged in soil type from waterlogged scald to deep drifting sand.
“Some paddocks that we consider 60 per cent paddocks – that is, sown at 100 per cent but only about 60 per cent is harvested – germinated and established at 100 per cent paddock levels,” he says.
“We had calving cows grazing the mouldboard ploughed and seeded barley at a rate of one cow per hectare four weeks after sowing, which is earlier than usual and helped to fill an autumn feed gap. But, most importantly, we showed we could mouldboard plough and seed in one pass.”
David says he plans to use the system across about 3000ha of his 5000ha Esperance property in the next few years.
The first year was cost neutral because he used low fertiliser rates and no chemicals at seeding.
“We saved money in no extra passes for seeding, packing or spraying big broadleaf weeds this season,” he says.
“Extra nitrogen mineralisation from the mouldboard ploughing has also significantly cut our fertiliser bill. Any yield benefit in this first year will be all profit, and we will get the cumulative benefits of mouldboard ploughing over the longer term.”
David says a month of preparing machinery for the one-pass operation was worth the effort to prove the concept would work. He will streamline the system for future years.
DAFWA researchers will monitor this year’s yield responses from the one-pass systems.
University of South Australia research fellow Dr Chris Saunders, who has a background in agriculture and agricultural engineering, visited Mic and David during May.
His visit was part of a GRDC-funded WA project investigating the selection, set-up and use of mouldboard ploughs.
Dr Saunders says the project aims to better understand the key issues growers experience when they start using mouldboard ploughs and their results.
He will also review the performance of currently used ploughs to achieve optimum soil inversion for burial of weeds and burial or mixing of non-wetting sands.
His report to the GRDC will highlight potential improvements – including plough choice, set-up or modification – and longer-term research needed to improve the design of the plough parts for conditions in WA’s southern and northern wheatbelt.
More information:Mic Fels,
08 9078 3014,
David Cox, 0429 008 638,
08 9083 1111,
Dr Chris Saunders,
08 8302 3664,
Ground Cover Supplement ‘Water Use Efficiency’
for more information: www.grdc.com.au/GCS103
GRDC Project Code USA00013
Region West, North, South