What is in this article?:
- Including soybeans in crop rotation provides advantages
- Rotate crops and tillage
- Conditions that favor soybeans
In addition to increasing corn yields and cutting nitrogen expense, keeping soybeans in the rotation lowers next year’s corn rootworm management costs, says Ken Ostlie, University of Minnesota Extension entomologist. “Rotation resets the population of corn rootworms in a field, so you can get by with fewer rootworm inputs the next year. You can eliminate insecticide use, or plant all non-Bt corn that first year.”
Keith Schrader, farmer from Nerstrand, Minn., has learned he must rotate to soybeans for long-term rootworm control, since he’s had resistant rootworms on continuous-corn acres.
Conditions that favor soybeans
Among 600 farms in south-central Minnesota, corn earned $59 to $147 per acre more than soybeans from 2010 to 2012, says Mark Wehe, Minnesota Farm Business Management educator in Faribault. Corn-on-corn acreage jumped, especially on highly productive fields, where the advantage for corn was even greater.
A soybean-to-corn price ratio of 2.3 or greater favors more soybeans in the rotation; that appears to be the trend in 2013 and 2014. University of Illinois 2014 crop budgets suggest a profit advantage for a corn-soybean rotation over both corn-corn-soybean and continuous corn. An average corn-to-soybean yield ratio of 3.3 or greater favors more corn in the rotation, while a lower yield ratio favors a traditional corn-soybean rotation.