Established 1896
The Old Rotation, established in 1896, is the oldest continuous cotton experiment in the world and the third oldest field crop experiment on the same site in the United States. It was placed on the National Register of Historical Places in 1988.
The “Old Rotation” is one of the earliest experiments to demonstrate the value of rotating cotton with other crops and including nitrogen-restoring legumes. It provided key evidence that rotating with legumes can sustain and even improve cotton and corn yields in Alabama soils.
Data from this long-running test have supported numerous scientific, educational and popular publications on cotton production, cover crops, soil fertility and sustainable agriculture.
Because the cropping systems have changed very little over time, the experiment continues to track the long-term effects of rotation on productivity, soil health, environmental quality and sustainability.
Located on one acre of Pacolet fine sandy loam at Auburn University, the “Old Rotation” includes six cropping systems across 13 plots. It features rotations with corn, soybean and small grains, along with winter cover crops, mainly winter legumes. The site is positioned at the junction of the Southern Piedmont and Gulf Coastal Plain regions.
*Older experiments are the “Morrow Plots” at the University of Illinois and the “Sanborn Field” at the University of Missouri-Columbia.
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By the late 1800s, most arable land in the Southern United States had been cleared for cotton and corn. Up to that point, almost no lime or commercial fertilizers were used. Most farmers still relied on “slash and burn” methods, moving on to new land once the soil was exhausted.
However, by the end of the 19th century, there was no new land left to move to. Existing farmland was rapidly degrading due to practices like fall plowing and leaving fields bare until spring planting. By 1910, Alabama had more than 4 million acres each of cotton and corn under cultivation.
Around this time, Land Grant Universities and Agricultural Experiment Stations began promoting scientific approaches to farming. In 1896, J.F. Duggar, a young professor at the Agricultural and Mechanical College of Alabama (later Alabama Polytechnic Institute, now Auburn University), proposed a new idea. He believed that Alabama agriculture would thrive only “when her fields are green in winter.”
To test his theory on winter cover crops, Duggar launched an experiment near campus. That project became what we now know as the “Old Rotation.”
Join Associate Professor Audrey Gamble for an in-depth look at the “Old Rotation”.
View and download the "Old Rotation" brochure, which features insights such as average yields and and trends.
