Are extra tillage passes worth it? The Univ. of Illinois Farmdoc Daily crew unpacked that complex question during a recent webinar recapping a decade of data from the Precision Conservation Management (PCM) program.

The PCM program — considered the premier conservation program of the Illinois Corn Growers Assn. and Illinois Soybean Assn. — collects data from every field pass, including tillage passes, fertilizer passes, chemical passes, harvesting and planting. They attribute a cost to each pass and ultimately add everything up to see which system gives farmers the most bang for their buck on Illinois fields.

“Our goal is to help farmers understand what conservation practices mean for them,” says Laura Gentry from the Illinois Corn Growers Assn. “Given today’s environment, you can understand why it’s important. This is one of the worst ag economies we’ve seen since 2010. Farmers need to think about how to be a low-cost producer.”

Under the PCM program, data was collected from over a thousand Illinois “high SPR” and “low SPR” cornfields. SPR stands for soil productivity rating. “It’s an evaluation of how profitable we think the soils of a field are,” Gentry says. If the SPR rating is greater than 135, it’s considered high.  

For corn production on high SPR fields, no-till came out on top as PCM’s strongest system in recent years. But strip-till led the pack on low SPR fields.

“We see strip-till doing really well on low SPR fields,” Gentry says. “Strip-till performed well in 5 of 10 years, including the 3 most recent years. Strip-till is the standout for this dataset.”

Strip-till on low SPR cornfields averaged 206 bushels per acre from 2015 to 2024. That’s 13 higher than no-till, 9 higher than 1-pass light tillage, 7 higher than 2-pass moderate tillage, 1 lower than 2-pass light tillage and 5 lower than 2-plus tillage passes.

These results remind me of a recent interview I did with Westin Arseneau, who farms in Iroquois County, Ill. For years, he was conditioned to believe that you can't strip-till unless you have ideal fields (high SPR) and good drainage. But he learned that wasn’t the case at all when he gave it a try on his poorly drained soils.

“We’ve had 3 record crops in a row,” Arseneau says. “Before strip-till, we were around 180 bushels per acre. Now we’re well above that. I learned that you don’t have to have the perfect soils to make strip-till and no-till work. In our experiences, it seems like it works even better in the marginal stuff.”

As the saying goes, numbers never lie. Strip-till delivers ROI even in the most challenging conditions — both economically and environmentally. Check out the PCM webinar replay when you get a break this harvest season. There’s some revealing data in there showcasing the economic impact of strip-till and other conservation practices.