To preserve soil nutrients and increase the number of bushels of corn or wheat harvested per acre, farmers rotated what they planted. For example, in one field, a farmer planted oats one year, wheat next, and corn the next. Then, for two years, the farmer let clover or alfalfa grow to put nitrogen back in the soil. The alfalfa would also provide hay to feed horses, mules, and cattle.
Written by Claudia Reinhardt.