Why farmers skip crop rotation and just grow corn every year, same fields
MORRISBURG — Though it defies conventional crop-rotation wisdom, growing corn in the same field year after year has always had its place. West Quebec’s Peter Finlayson recently highlighted his success with the politically-incorrect practice of growing “corn on corn” for a whopping 50-plus years.
Finlayson says his yield today averages about 165 bu/ac from the same 150-acre plot that has been pushing up corn since 1967. The Eastern Ontario 10-year yield average is 178 bu/ac.
“I obviously haven’t destroyed my land,” Finlayson, a former long-time hog and beef producer, told Farmers Forum.
Morrisburg-area cash cropper Warren Schneckenburger reported that his family historically grew “a crapload of corn on corn” until the early 2000s. “We had several farms that were 50 years’ continuous corn,” he says. They added soybeans to their production schedule in 2005, a change he says was compelled by modern corn hybrids, which became less feasible to grow continuously in combination with conventional tillage. Advanced corn genetics began to produce corn crops with so much more leaf and stalk material (stover), the material tied up precious nitrogen when plowed under each fall. “The nitrogen penalty from burying all those corn stalks was like, 50 bushels per acre,” he says.
Schneckenburger has since switched to strip tillage, allowing the farm to overcome the previous bottleneck. The new technique leaves the corn crop residue on the soil surface, and a row cleaner implement is used to move that material aside. “That has made getting an established stand very easy and we’ve had very good success with continuous strip-till corn,” he says. The farm now has some five-year corn-on-corn stands, he says, “and we still haven’t hit a yield penalty yet…. and that’s pretty fantastic.”
He now adheres to a six-year overall rotation — with three years in corn, followed by two years in soybeans and one year in wheat. On a more limited acreage, he intends to grow corn-on-corn for as long as he can.
The end result: “We’ve managed to maintain 60 % of our fields in corn, and the rest is split between beans and wheat. It’s been working very well for us, but strip-till is not for everyone.”
He noted that soybeans all go into the export market, and this typically means a basis hit when compared to corn. “Corn is still king in Eastern Ontario over the last 10 years,” he says, even if the market has been “a little topsy-turvy” more recently.
Corn-on-corn production “can be done, but generally, you need 25 to 30 pounds more per nitrogen per acre,” Eastern Ontario Pioneer agronomist Paul Hermans says.
Hermans also advises that continuous corn growers use triple-stacked hybrids for lower-ground protection because there’s a greater chance of corn rootworm resistance and other diseases like northern leaf blight in a crop grown year after year. He also notes that a corn-on-corn crop tends to be less resilient when stressed by drought.
At minimum, growing corn-on-corn means two successive corn crops in two consecutive years, and most growers typically don’t push it beyond that, according to Hermans, who estimates that no more than 10 % of Eastern Ontario corn acres is second-year corn or beyond. The amount of corn-on-corn acres will vary, he says, depending on commodity prices — the spread between soybean prices and corn prices. The practice is also tempered by the substantial amount of livestock production that still occurs in Eastern Ontario, guaranteeing the need for hay and other crops to be part of the local rotation anyway.
Ironically, Eastern Ontario could potentially see a few more corn-on-corn acres planted this spring, he suggests, because of an uptick in white mould observed in the 2023 soybean crop.
However, in the end, the data still suggest an annual corn-beans-wheat rotation performs better than a constant corn monocrop, he says.
Crop consultant Gilles Quesnel agrees, pegging the yield advantage of corn grown in rotation at 5 to 10 % over corn-on-corn.
OMAFRA corn specialist Ben Rosser also noted the “slight yield lag” for corn-on-corn production. “Growers have their reasons for growing corn-on-corn, whether they need the feed for livestock on a limited land base, or feel that corn is the most economically competitive crop on their cropland,” Rosser says.
Bobcaygeon-area beef farmer and cash cropper Barry Baxter says he grows corn-on-corn in a two-year rotation, cycling through soybeans, then seed-grade barley and rye, and then and back to hay ground. He does it all in two-year increments through a six- or eight-year process. “A lot of it’s because I’m lazy,” he quips, “and a lot of it’s because it’s a lot easier to not switch every field around every year.”
He’s had no issues with this rotation, though “some people think I’m crazy.”