(Editor's note: We posted this article in hopes of generating some discussion about whether the definition of no-till has really changed. What's happening in your region?)
The highly touted no-till farming era has mysteriously failed to materialize, according to University of Illinois agronomist Emerson Nafziger.
Despite the emphasis on the once-revolutionary farming practice in which seeds are drilled into last season’s stubble, Illinois farmers are tilling away.
Nafziger, speaking at a field day here, discussed the phenomenon of changing expectations in Corn Belt farming.
“Thirty years ago, if you listened to the right people back then, we believed all that we would need is a tractor big enough to pull our planter, and that would be the only two pieces of equipment we would have,” he said. “And it didn’t happen. In fact, I suspect we have more horsepower per acre in Illinois now than we did back then.
“We certainly have a lot bigger tractors. And once you get a really big tractor, you have to get something to pull. And the equipment companies have been very happy to make more iron.”
Illinois is regarded as the No. 1 no-till state, in terms of acreage planted. And though many growers consider themselves no-till farmers, the facts belie that, according to Nafziger.
“We don’t have as many tractors as we had, but certainly we have more ability to mechanically disturb the soil now than we’ve ever had before,” he said. “And that seems odd, because we were on the path to do less tillage. Last fall, we did more tillage in Illinois than we’ve ever done in my 30 years here. And we all felt really good about that. There was a pent-up demand to do tillage.”
One reason for the phenomenon is the changing idea of what is no-till, according to Nafziger.
“The other thing that has changed is our definition of no-till,” he said. “Tillage is no longer a practice. It’s how much residue you’ve left on the surface. That’s how it happens that even though I made the statement that we’ve got the ability to till more than ever more, a farmer who says he has no-tilled for 20 years, you look at the field and say, ‘That’s not no-till.’
“You realize you can disk stalks in the fall, you can deep-rip, you can do lots of things and in the spring say, ‘I did that no-till.’ In a way, that’s a good thing, because the dogmatism that you’ve got to slot-till without doing any tillage doesn’t always work.”
Farmers concerned about soil condition have been getting ahead of themselves, often disturbing their soil too much in the fall, Nafziger believes.
“We had fields that were ready to plant in November last fall,” he said. “And what happened this spring? It got to be May 1 and much of Illinois didn’t have the crop planted and they panicked. And they went out there and undid almost all of the good they did the fall before with tillage.”
Farmers may want to consider the effects of tillage on their soil, especially when considering tilling in the fall to produce a good seedbed for the following year.
“The amount of compaction we do in our soils with the heavy equipment we use, it produces compaction in the soil that is never going to be relieved by natural forces,” Nafziger said. “The heavy axle-load of a combine will put compaction to the soils to a depth of 20 inches or more.”
Claypan soils such as those present in southern Illinois are especially subject to compaction. Nafziger said efforts have been made to improve the character of the soil, but they did not “pan” out.
He cited an experiment in which fields were moldboard-plowed at a depth of 36 inches, in an attempt to provide a superior seedbed. The result was less than permanent.
“The experiment ended without a lot of people doing that,” Nafziger said. “What they have found in these soils is, if you disturb that claypan, it seems to reform again.
“I don’t know what we expected this harrow to do. It can only make the soil loose to the depth you’re operating it. It can’t reach down. And it’s not clear that most of the time roots have a big problem.”
He said most farmers who have abandoned no-till in favor of some type of tillage have done so because of reduced stands.
A recently explored option is “vertical tillage,” a form of shallow tillage done at relatively high speeds. Another innovation is “bio-tillage,” which involves the planting of crops — usually a specific radish variety — that make channels in the soil by root growth.
“I really like the term,” Nafziger said. “It means letting something alive do your tillage for you. The idea is to plant them and let them grow deep. We have somebody up there trying it this past fall. I think it’s an interesting idea.”