With record corn yields resulting in a record amount of corn stover, Penn State University Extension suggests that growers can manage extra residue by partially harvesting it.
Penn State agronomist Greg Roth said the university had recently completed a 5-year study and found no negative effects related to soil carbon or corn yields from 50% stover removal in a no-till system. In fact, in some wet springs there was an improvement in corn growth from the stover removal.
“We managed potassium carefully and applied extra potassium to compensate for the removal,” Roth says.
But when we shared the story on our website, several no-tillers were skeptical.
“Why have we been taught for 50 years to conserve as much stover as possible, to conserve soil from wind and water erosion, as well as nutrients, and now we learn we can sell half of it with no harm done to the soils?” one reader responded. “It may be OK for the short term, but when you mine soils they go down hill.
“It still looks like trading dollars for something that cannot be bought in a ‘bag or a buggy.’”
Another reader pointed out that removing stover, and the organic matter it helps build, would cause soil pH levels to increase, resulting in more lime applications and soil compaction.
Retired Ohio State University ag engineer Randall Reeder agrees that no-tillers are correct to be concerned. Leaving all the residue will help increase organic matter, “and for most farmland, you can never have too much organic matter,” he says.
But not all growers think it’s a terrible idea. A no-tiller in southwestern Ontario says growers in his area created a co-op to possibly build their own plant to process corn stalks into saleable sugar. In their model, the sugar is removed from the stalks and most of the fertilizer is returned to the ground.
“I don’t think removing a few corn stalks 1 year in 5 will reduce my organic matter,” he says. “Maybe it’ll just require that I continue using cover crops and no-tilling to maintain my soil.”
In either case, it’s great to see this type of dialogue between no-tillers, so that everyone is forced to reflect on the management practices that are going to give them the most benefit. If you’d like to join the conversation, scroll down to the bottom of the page where you can leave a comment.