Although more than 40 percent of soybean acreage in the United States is now no-tilled, debate still centers on whether no-tilling or conventional tillage produce the best soybean yields. Extensive data crunching is swaying the debate toward no-till.

Farmers, crop advisors, agronomists and seed breeders have debated the merits and drawbacks of no-till versus conventional tillage for years. “The overall goal is to manage production for optimum yield and economic return,” notes Michael DeFelice, senior marketing manager for Pioneer Hi-Bred International Inc.

DeFelice says his review of existing yield research points toward the benefits of no-till. He compared studies of soybean yields in major growing areas by tillage system. The bottom line: soybean yields tended to be greater under no-till systems; in some studies the yield advantage pushed 5 percent.

Favorable Conditions.

“The South and the West saw greater soybean yields under no-till,” DeFelice says. “Yields were similar in the central United States, and no-till typically produced lower yields than conventional tillage in the northern United States and Canada.”

The area of positive soybean yields under no-till extends into the Ohio and Missouri river valleys of the Midwest and Great Plains. A narrow transition zone extends from the northeastern United States to the upper Midwest.

The objective of DeFelice’s research was to examine no-till’s effect on soybean yields relative to conventional tillage in different regions of the United States. He then mapped the data to identify geographic and environmental patterns in the performance of no-till versus conventional tillage on soybean…