Why Are You Still Tilling Now?

Purdue agronomist suggests it may not be necessary in some cases.

Published on: Nov 5, 2010
Harvest ended at a record pace, especially for corn. Soybean harvest, even replants in wet spots and doublecrops, are now nearing completion. So there's a lot of farmers with a lot of time on their hands, still good weather and lots of empty fields. Even though it has been extremely dry, limiting how well some tillage tools work, many farmers have still taken to the field, tilling up soil.

Tony Vyn, Purdue University tillage specialist, suggests that a farmer ought to ask himself why he is doing so. Harder pulling conditions likely means he's using more fuel, although that may be offset, mentally at least, by strong commodity prices to pay for extra fuel costs.

Farmers often ask questions for which there are no research answers. There is solid data going back 35 years now supporting that it is unnecessary to till soybean land going to corn in the fall, yet farmers don't ask that question. Instead they jump on the tractor and head out to chisel or plow, or do some sort of disking or vertical tillage operation.

"Good weather conditions and an early harvest are, by themselves, insufficient justification for intensive fall tillage for 2010," Vyn stresses. Instead, he urges that before you fire up the tractor, fill the fuel tank and hook up to the implement of your choice, you seriously think through what you're about to do.

"Other management factors like crop rotation, hybrid selection, and nutrient management will likely have much more impact on corn yield in 2011 than the tillage system," he says. And Vyn is not shy to call fall tillage in these instances what he truly believes it is: "Recreational tillage is expensive entertainment," he says.

Vyn points to 35 years of crop tillage research on a dark, 4% organic matter soil at the Purdue University Agronomic Research Center near West Lafayette. The flat, dark soils were originally considered by many to be unsuitable for no-till.

For soybeans after corn from 2000 through 2009, no-till yielded 201 bushels per acre, vs. 202 for moldboard and 204 for chisel plowing. In 2010, no-till yielded 220 bushels per acre, vs. 222 for chisel and 215 for moldboard plowing. The long-term results during this 10 –year period are not significantly different, meaning that even on this soil, there is not a significant advantage for tillage over no-till for corn following soybeans.