Crop rotation is a farming method to manage diseases by changing the crops grown in a field each year. In Ohio, farmers have shifted from diverse rotations to mainly growing corn and soybeans. Scientists studied how this change affected the fungi in the soil under corn plants. They found that fungal communities were different based on location, rotation type, and time. The diversity of fungal species was higher in the corn-soybean rotation. Certain fungal species were more common in the corn-soybean-winter wheat rotation, while others were more common in the corn-soybean rotation. The presence of specific fungal species was linked to soil organic matter but not to corn yield or soil nutrients.