Growers are finding better growth management with coulter systems.
Strip-till is growing in popularity amoung field crop farmers in Ontario, Canada. However, where shank-based systems once dominated, coulter systems are gaining in popularity.
Shanks are not being completely overlooked, though. While coulter-based strip-tillers offer more effective fertiliser management and versatility, the former can still help address soil management issue – particularly in heavy clay.
For Morley Wallace, a grain grower and owner of GPS Ontario – a small precision-ag company – coulter strip-till designs offer more efficient fertiliser management. In a series of corn trials, Wallace’s says coulter systems generated regular yield boosts of up to 20 per cent. This happened despite reducing the amount of applied fertiliser in those strips.
The results, he says, stem from the shallower and more vigorous mixing of fertiliser in combination with existing precision management (notably variable-rate) technologies.
“Fundamentally we need to mix the soil […] we can do this with 50 per cent less fertiliser,” Wallace says.
Tony Balkwill, an agronomist and operator of Nithfield Advanced Agronomy – a 650-acre private research farm – also sees coulters as the preferred tool for fertiliser management. He changed from shank-based systems in order to bookended fertiliser in 2 bands on either side of the strip.
This makes it easier for roots to find the fertiliser while simultaneously creating a buffer zone in case the planter goes off-track – something which, as Balkwill describes, does happen as the vast weight of large, modern planting systems makes them sway off-course despite the presence of GPS and auto-steer technology.
He adds the mixing action of his coulter-based system is also very effective at clearing crop residue within the strip. This aids in soil heat retention early in the growing season.
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Jake Munroe, soil fertility specialist in field crops with Ontario’s provincial agriculture ministry, says his experience investigating strip-till in research plots throughout the province illustrates the effectiveness of machinery depends on what the grower is trying to do – and what soil they’re trying to do it in.
Shank based machines, he says, can do a good job of breaking-up heavier soils, particularly in autumn since large clods will break apart over the winter. Coulters tend to be used more often in sandier ground and in the spring.
Regarding fertiliser incorporation, Munroe says he has seen cases where growers have seen different physical responses between test strips worked with coulters and shanks.
“It’s worth thinking about. What are our maximum safe rates for banding? […] if we’re looking at shank-based fertiliser application, consider what depth that shank is at,” he says.
Tyler McBlain says they have never tried shank-based strip-tilling on their grain farm because shank systems on other equipment (e.g. rippers) cause smearing in their heavy clay soil. They instead run a shallow coulter system as either a single-pass on soybean stubble in the spring, or as a dual spring and fall pass if managing heavier residues.
“It seems to work a lot better. We go shallow because we don’t have a lot of topsoil,” McBlain says. “We’re just trying to warm up that top little band.”
Strip-till management has been around for some time, but the adoption of the technology and resources promoting it have lagged behind other parts of North America, such as farmers in the American state of Wisconsin. However, increasing interest is spurring Munroe and his ministry colleagues to develop more outreach tools for other farmers.
“Over the last couple years we have been trying to get more producers on panels who are at different stages of strip-till adoption. These kinds of events are a great resource,” he says.
“It’s a big change potentially to the operation and I certainly think its worth some time and money. We’d like to create more of a hub for resources for producers here in Ontario.”