The Canadian experience: it makes a difference
GroundCover™ Issue: 48
The challenges presented by low-moisture, high-erosion environments are common to both the Canadian prairies and large proportions of Australia’s cropping regions.
To share the lessons learned in Canada, where the no-tillage system has been long established, the Victorian No-Till Farmers Association conference heard from Canadian no-tillage expert Dr Guy Lafond, who has completed a 14-year study comparing no-tillage with other systems.
Dr Lafond, a Production Systems Agronomist and specialised crop coordinator with Agriculture and Agri-Food Canada, has compared the long-term benefits of no-tillage on adjacent paddocks in Saskatchewan.
The study was initiated in 2002 when no-till veteran Jim Halford leased a paddock next to his long-term, no-till paddock near Indian Head and switched it to the no-tillage system.
Among the findings was a dramatic difference in yield, especially when no nitrogen fertiliser was applied: Mr Halford’s original land (under no-tillage for 20 years) was sown to spring wheat and yielded 2.87 tonne/ha (42.6 bushels/acre) versus 1.76 tonne/ha (26.2 bushel/acre) on the newly no-tilled fields.
Dr Lafond said the results of this study demonstrated that the agronomic and economic benefits with direct seeding accrue over time.
At the conference, he presented a summary of the results of his 1986-1998 comparative study of tillage systems and crop rotations at the Indian Head Research Farm in Saskatchewan.
In Saskatchewan, 40 percent of cultivated hectares used no-tillage, a 2003 survey revealed. The province is one of three prairie provinces and accounts for 48 percent of all cultivated land in Canada, where no-tillage has been widely practised for about 15 years. Its adoption has been spurred on by the determination of several no-tillage pioneers and major changes to government policies aimed at tackling the region’s serious soil degradation.
The Indian Head study compared no-tillage, minimum tillage and conventional tillage on three crop sequences. Water use, weed and disease management and row spacing were some of the many aspects it covered. On yield, among the results recorded were a nine percent yield advantage for field peas and 11 percent for flax, averaged over a 12-year period.
Economic comparisons of the three tillage systems found that net returns were highest for the minimum-tillage and no-tillage managed cereal/oilseed/pulse rotation and lowest for the monocultural cereal rotation.
Conventional tillage management practices showed the highest level of financial risk for all crop rotations and grain price scenarios. More recently, further research provided an insight into the impact of standing stubble on wind speeds and therefore evaporation rates.
“If you have 30 to 35cm stubble, the wind speed on the soil surface is reduced by about 70 percent,” he said. “Which means that you significantly reduce water evaporation in the soil, which means the water stays in the soil longer for the plant to capture. Any time you can funnel more water to the plant you will derive more yield.”
Speaking after the conference, he said that despite the vastly different climates of the grain regions of Canada and Australia, the needs for water conservation and soil improvement were common to both, and Australia’s poorer soils made the case for switching to no-till even stronger than in Canada. “The soils are much more fertile in Western Canada . . . Here they talk about soils with half a percent organic carbon.
“Unless you have beach sand, we don’t have much of that. Around Indian Head, we have around three to four per cent organic matter.”
Water conservation was the prime driver of no-till gains in Western Canada in the short term, “but from what I can see the benefits that are being derived here are from rapid improvements in soil structure”.
For more information:
Robert Ruwoldt, President, Victorian No-Till Farmers Association, firstname.lastname@example.org
Region North, South, West