Adding crops to a corn–soybean rotation can improve soil function, spread risk and reduce some input requirements, but the economic result depends on whether the additional crops perform and have a reliable market. South Dakota research examined both farmers’ experience and field-trial evidence.
What farmers reported
A 2018 survey of 680 producers in eastern South Dakota found that 58% used a corn–soybean rotation, 18% continuously cropped a single crop and fewer than one-quarter used more diverse rotations. More than half of the farmers who had diversified had maintained the practice for over ten years, and many reported improved yield and profitability.
Adoption was more common among long-term users and on marginal, dry or sloping land, where soil protection and resilience may be particularly valuable. Survey responses show producer experience and perception, however; they do not by themselves prove that diversification caused every reported improvement.
Field results add a second line of evidence
In a separate experiment, researchers compared a four-year corn–soybean–spring wheat–field pea sequence with a simpler corn–soybean system under reduced nitrogen. Corn following peas outyielded corn following soybeans, wheat following peas outperformed wheat following oats, and soybean yields were higher within the four-crop rotations.
The diversified sequence also reduced input costs and improved calculated economic returns in the study. These results are encouraging, but they remain location- and season-dependent. A practical transition needs suitable varieties, equipment, agronomy and buyers for the additional crops—not diversity for its own sake.
Read the original report: Phys.org.