DAVIS, CALIF. — An indigenous variety of corn in Mexico fixes nitrogen from the air instead of getting the nitrogen from synthetic fertilizers. Researchers believe cross-breeding this trait into conventional corn varieties could reduce fertilizer use.

“Legume crops like soybeans have nodules on their roots that harbor bacteria that can turn nitrogen in the air into a form the plant can use,” said Alan Bennett, Ph.D., distinguished professor of plant sciences at the University of California, Davis. “For cereal crops like corn, farmers must rely primarily on nitrogen fertilizers.”

A team of researchers from UC-Davis; the University of Wisconsin, Madison; and Mars, Inc. are working with the tropical corn that grows in the Sierra Mixe region of Mexico. It obtains 28% to 82% of its nitrogen from the atmosphere through developing 8 to 10 aerial roots that never touch the ground. The roots secrete a gel-like substance that attracts bacteria, which in turn may transform nitrogen.

The study was published Aug. 7 in PLOS Biology and may be found here.

 The corn grows more than 16 feet tall, which compares to conventional varieties that grow 12 feet tall. It also takes eight to nine months to grow, which compares to three months for conventional corn.

Besides reducing fertilizer use, the trait also may assist in improving food security.

“Corn yields in developing countries are one-tenth of those found in the U.S., due both to variety development and access to affordable nitrogen fertilizer,” said Allen Van Deynze, Ph.D., director of research at the UC-Davis seed biotechnology center. “This discovery opens the door to significantly improving the genetic potential and food security for these countries.”