Vertical Tillage A Step Backward

“A lot of this technology is coming out. It may seem new, but it is really old technology being re-introduced as something new. Where does it have a fit in Western Canada under our conditions?”

— Blair McClinton

With growing interest among equipment manufacturers and some producers in the concept of vertical tillage, long time advocates of zero-till cropping advise farmers to look before they leap at this re-launched technology.

The concept of using a relatively low disturbance coulter or knife to fracture the soil profile doesn’t sound bad, say soil conservation specialists, but in limited research, there doesn’t appear to be a general benefit. And if the treatment causes moisture loss, it could be a negative.

Most popular in corn and soybean growing regions, vertical tillage may work well on some soils and for certain applications, but any suggestion that widespread adaptation of vertical tillage is of value for grain and oilseed production may be premature, they say.

So what is vertical tillage? Systems vary depending on manufacturer, but the idea is to mount wavy coulters — or in some cases knives — on a tool bar and use those coulters to break down crop residue and blacken a bit of the soil. And although the coulter or knives run fairly shallow — two to three inches deep — the action of the tool fractures the soil profile downward, or “vertically,” improving moisture infiltration, crop root development and nutrient uptake. In some systems there may be harrow tines that follow the coulters, as well as a circular or roller harrow behind the tined harrows, which help level the field.

Several equipment manufacturers in Canada and the U. S. have vertical tillage equipment. Salford, in southern Ontario, which has been building a vertical tillage toolbar for corn and soybean growers for years, is trying to crack into the Prairie market. Till-Tech Systems of Straffordville, Ont., makes a vertical tillage tool. In North Dakota, Summers Manufacturing at Devils Lake, and Wil-Rich of Whapeton, have vertical tillage equipment, along with Yetter Manufacturing of Colchester Illinois, Brillion of Wisconsin, Great Plains of Salina, Kansas, and Case IH, to name a few.

Western soil scientists and soil conservation specialists who have long advocated the value of no-till farming and direct seeding say while the tillage practice may have benefit in soils and moisture regimes where corn and soybeans are produced, there is no clear evidence vertical tillage will benefit general grain and oilseed production in Western Canada.

Blair McClinton, executive manager of the Saskatchewan Soil Conservation Association, says most of the interest in vertical tillage is being fueled by equipment manufacturers trying

to re-package existing technology, without benefit of research that shows it does any good. Some of the earliest patents on wavy coulters date back more than 60 years.

“The first question is, in our conditions, with no-till farming,

do we really see a need for it?” says McClinton. “A lot of this technolo-

gy is coming out, it may seem new, but it is really old technology being re-introduced as something new. Where does it have a fit in Western Canada under our conditions?”

He says long term research has mixed results on whether soil compaction is a widespread problem, and many of the seeding systems used today with different openers and sidebanding attachments do create a fair bit of disturbance in the top three or four inches of soil. He says farmers have to consider whether vertical tillage might loosen the seedbed too much. Probably a bigger concern is what impact it might have on soil moisture loss.

Guy Lafond, an Agriculture Canada soil researcher at Indian Head, Sask., says he hasn’t seen any research that supports the value of vertical tillage in Western Canada.

“It sounds like something that uses a lot of diesel fuel to me,” he says. “As a scientist you can never rule anything out, but I would need to see some good solid side-by-side research that shows it makes a difference. To me the first question is what are we trying to fix? Is there a problem to begin with?”

Lafond, a long time advocate of no-till farming, sees interest in vertical tillage as technology going in the wrong direction. “If we are entering a period of climate change, we will need to pay even more attention to moisture conservation,” he says. “As crop producers we need to remember it is water and nitrogen that drive everything.”

Dave Franzen, extension soil specialist with the North Dakota State University in Fargo, says vertical tillage has a demonstrated value in some soil types, but he hasn’t seen where it has much value in North Dakota (and likely many parts of Western Canada).

A lot of farming areas have clay soil, but not all clays are the same, says Franzen. The Georgia clay is different than the Illinois clay and that is different than the Michigan clay, which is different than the North Dakota clay.

“If you look at the actual chemistry of the clay soils, they all behave differently,” says Franzen. “In North Dakota and I suspect in much of Western Canada we have smectite clay, which shrinks and swells at different temperatures and moistures, so the issue of compaction is not the same in these soils as it might be in some other region with different types of clay.”

Unless there is some type of sodium component in a soil, he is “pretty skeptical” of claims of soil compaction.

He says vertical tillage may have an application in very specific circumstances, but as an advocate of no-till farming, he is more concerned about maintaining crop residue and conserving moisture.

DeAnn Presley of Kansas State University is one soil specialist doing side-by-side trials to test the value, if any, of vertical tillage. She had one small project last year comparing vertical tillage with conventional and no-till corn systems, and saw no significant differences in that one-year trial. “Of course in research, results from one year really isn’t an indicator, so we plan to continue trials to see if there are any benefits,” says Presley.

With her project funded by Kansas corn growers, most of the trials will involve vertical tillage in corn production, but she does hope to expand it to wheat production in the future.

“There are a number of claims, but the objective of the research is to see what benefits there might be with vertical tillage,” Presley says. She wonders, if one of the claimed benefits is to manage residue so it leaves residue on the surface to hold soil, wouldn’t it be better to leave the residue attached to the roots? And she’ll also be looking at the impact of vertical tillage on soil compaction. One of her colleagues in Nebraska said he had looked at vertical tillage in corn production under wet conditions and actually found that compaction was worse after the tillage operation. So that is another claim to be evaluated.

SUPPORT FOR VERTICAL TILLAGE

Jim Boak, sales manager for Salford RTS, says while “tillage” is used to describe the technology, the amount of soil disturbance caused by many treatments can be relatively small.

“Vertical tillage tools are ideal for incorporating fertilizer and seed,” he says. “Some of them can even manage residue with almost no tillage. The RTS for example on 14-inch coulter spacing does an excellent job of residue management.”

On 14-or 15-inch spacing, the coulter setup on a 50-foot machine would limit soil contact to about eight inches of soil over 50 feet.

“Here is the math for that example,” says Boak. A 50-foot RTS toolbar, with coulters on 14 inch spacing, requires 44 blades each with a 4.5 mm width. That’s 198 mm in total, or 7.92 inches.

“How many soil microbes can you hit with an eight-inch wheel spaced every 50 feet at 11 mph and 2.5-inch operating depth?” says Boak. “That is a question looking for an answer.

“The practice shouldn’t be called vertical tillage, but residue management and it is all about controlling yield limiting factors to obtain the highest possible yield at the lowest possible cost to the producer. We can have our cake and eat it too — by having some influence over yield limiting factors in a no-till environment.”

Lee Hart is a field editor for Grainews in Calgary, Contact him at 403-592-1964 or by email at [email protected]

About the author

Field Editor

Lee Hart

Lee Hart is editor of Cattleman’s Corner based in Calgary.

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