The early-season onset of high temperatures and lack of rain limited both root growth and shoot growth in 2012. Corn and soybean varieties differ in their relative rooting ability under stress conditions, but rooting in all varieties after the early seedling stage depends on energy reserves coming from shoot growth.
"The near-surface soil was so dry, lack of tillage meant more resistance to root penetration, meaning corn or soybean plants in those fields sometimes experienced more drought stress before flowering than other tilled fields, despite the crop residue cover," Vyn said. "But we may never see such a severe, early drought occur with that combination of timing and high temperatures again.
"A later-season drought occurring after deep early root establishment would have favored no-till more."
If farmers decide to practice fall tillage, they can choose from several management techniques. Standard primary tillage procedures include using a disk, chisel plow, deep ripper, moldboard plow or strip tiller.
Vyn said agronomists favor strip tillage because it allows for minimal soil mixing and residue incorporation while preparing fields for earlier seeding of spring crops, and it can be combined with fertilizer application.
"It's a proven, versatile tillage practice that creates a warmer, drier zone of soil in the spring that ensures timely seed placement in both corn-soybean and corn-corn rotations," Vyn said. "Precision automatic guidance systems have also simplified crop row placement in the center of the loosened strips."
He said there's still time yet for farmers to decide whether fall tillage is needed for their fields and that they shouldn't rush the decision. With fall rains, farmers should be cautious and not rush fall tillage on soils that may be too wet.