As U.S. farms grapple with the increasing unpredictability of climate, researchers from the U.S. Department of Agriculture's Agricultural Research Service (ARS) are turning to ancient farming techniques to tackle modern challenges. Their latest findings reveal that diverse crop rotations — growing a sequence of different crops over time — can mitigate the risks of crop loss, improve soil health and increase the sustainability of agricultural systems in an era of more frequent adverse weather.

Crop rotation, a practice dating back thousands of years, has been proven to strengthen the resilience of farms against pests, diseases and erratic growing conditions. While the benefits of crop rotation are well-established, widespread adoption remains limited due to economic uncertainty, lack of incentives and insufficient data on long-term outcomes.

To address this, ARS agroecologists analyzed data from 20 long-term experiments, some spanning up to six decades, across North America. Their goal was to evaluate how diverse crop rotations impact both individual crops, like corn or soybean, and the entire rotation system under varying growing conditions. They found that crops grown in more diverse rotations consistently outperformed those in simpler rotations, especially during challenging growing seasons.

"Our results add to the growing body of evidence that is essential to removing the barriers that prevent adoption of sustainable farming practices," said ARS Ecologist Dr. Katherine Muller in a news release. "To our knowledge, no long-term, multi-site studies have attempted to understand the effect of changing the rotation on the performance of both the complete rotation and its component crops simultaneously."

The research highlights that the composition of the crop rotation plays a crucial role, with diverse rotations significantly reducing the risk of crop loss under poor conditions. However, transitioning to more diverse crop rotations presents hurdles for farmers, including increased management complexity, the need for new equipment and the challenge of growing unfamiliar crops. Despite these challenges, diverse rotations can lead to reduced reliance on fertilizers and pesticides — an attractive prospect as farmers contend with fluctuating nitrogen fertilizer prices.

The DRIVES Network (Diverse Rotations Improve Valuable Ecosystem Services), a collaborative effort involving ARS and universities across the U.S., is expanding its database to offer farmers practical insights. By analyzing long-term field experiments, researchers are quantifying the benefits and costs of diverse rotations while showing how they can reduce the vulnerability of farms to adverse weather patterns like droughts and heat stress.

"Long-term field experiments are national treasures for capturing dynamics in slow-moving variables like soil characteristics, or responses under erratic conditions, like droughts. Both of these variables are critical to understanding how agricultural systems can adapt to climate change," said Dr. Ann Bybee-Finley, a North Carolina State University agroecology professor who initiated this research during her postdoctoral work at ARS.

The DRIVES Network's findings, published in the journal One Earth, will continue to guide future research through partnerships with leading universities and institutions. Their work promises to give farmers data-backed strategies to manage the risks posed by an increasingly unstable climate.

The Agricultural Research Service, the USDA's chief scientific research agency, delivers solutions to agricultural problems impacting the U.S. economy. Each dollar invested in agricultural research yields a $20 economic return, making this work critical to the future of American farming.