Small Grains Gain Ground in Midwestern Crop Rotations

The traditional corn-soybean rotation in the US Midwest has been a dominant practice for over seven decades, but environmental concerns and declining crop diversity have sparked renewed interest in incorporating small grains into production systems.

Winter wheat, barley, oats, rye, and other small grains offer several benefits, including additional farm revenues, soil coverage during winter, improved soil health, diversified rotations, and enhanced weed and disease management. However, barriers such as infrastructure, market availability, crop insurance, and farm schedules favoring corn and soybean have limited their adoption in the region.

The predominance of corn-soybean rotations has created recurring management windows for summer annual weeds like waterhemp, while repeated reliance on herbicides can intensify selection pressure for resistant populations. Moreover, pest adaptation has challenged the effectiveness of the corn-soybean rotation for pest suppression, with pests such as corn rootworm and soybean cyst nematode adapting through different mechanisms.

Field experiments in Illinois have shown that winter wheat preceding double-crop soybean can reduce SCN egg densities by approximately 32% compared to winter fallow. This finding highlights the potential benefits of integrating small grains into crop rotations for improved pest management and reduced environmental impacts.