Sierra Mixe Nitrogen-Fixing Corn

Learn about a corn landrace developed in Mexico that supports nitrogen-fixing microbes on its aerial roots, allowing it to grow in nutrient-poor soils.

| Spring 2019

Most corn grows small "prop" roots, but Sierra Mixe corn uses them for nitrogen fixing, too. Photo by Flickr/Ton Rulkens.

A joint research team from the University of California, Davis; the University of Wisconsin, Madison; and Mars, Inc. recently described a landrace of corn in the Sierra Mixe region of Mexico that doesn’t just survive in low-nitrogen soil — it thrives. The cultivar looks quite unfamiliar compared with the mass-produced, conventional cultivars in the United States, growing more than 16 feet tall. It grows much more slowly than conventional corn as well, taking about nine months to reach maturity, rather than conventional corn’s three.

However, the most remarkable thing about the Sierra Mixe corn is how it obtains most of its nitrogen.

Sierra Mixe corn grows 8 to 10 aerial roots — rather than the one or two grown by conventional corn — that secrete a sugar-rich mucilage, which attracts nitrogen-fixing bacteria that then convert aerial nitrogen into a more usable form. In a simplified sense, the corn fixes nitrogen from the air, rather than the soil.

Incredibly fascinating in its own right, this corn also holds some serious potential for sustainable agriculture down the line. Nitrogen fertilizers are often financially inaccessible in developing countries, and producing them requires about 2 percent of the world’s energy supply, which contributes to global greenhouse gas emissions. If the Sierra Mixe corn’s nitrogen-fixing trait could be bred into cheap, conventional cultivars, it could dramatically increase yields in nitrogen-poor areas and eliminate the need for costly nitrogen fertilizers. It would also mean a more sustainable way to grow one of the world’s most mass-produced crops, and greater food security for developing nations.



October 19-20, 2019
Topeka, Kansas

Join us in the heart of the Midwest to explore ways to save money and live efficiently. This two-day event includes hands-on workshops and a marketplace featuring the latest homesteading products.


Subscribe today

Heirloom GardenerCultivate your love of historic plant varieties and traditional recipes with a subscription to Heirloom Gardener magazine today!

Don’t miss a single issue of Heirloom Gardener. Published by the editors of MOTHER EARTH NEWS, Heirloom Gardener provides decades of organic gardening experience from the most trusted voices in the field. Subscribe today and save as much as 38% off the newsstand price! Get one year (4 issues) for only $24.95!

Facebook Pinterest Instagram YouTube

click me