Corn variety gets nutrients from bacteria, potentially reducing need for fertilizer

The study describes the unusual corn variety, which obtains 29 to 82 percent of its nitrogen from the air, rather than through fertilizers. The plant produces a sugary 'goo' that oozes from aerial roots that grow from above the ground, and which attracts bacteria that can transform nitrogen from the air into a form that the plant can use. If this trait could be bred into conventional varieties of corn, it may reduce the need for added fertilizer and increase corn production in regions with poor soils.

Beans and other legumes have established beneficial relationships with communities of bacteria that provide them with nitrogen, but corn and other cereal crops traditionally lack these relationships. The commercial fertilizers required to grow corn come from fossil fuels, and their energy-intensive production uses an estimated 1 to 2 percent of the global energy supply. Scientists have been eager to devise a way for corn to take advantage of these nitrogen-producing communities. Prof. Bennett and his colleagues are interested to see whether other cereals, such as sorghum, can also use their aerial roots for a similar function.

"The idea that isolated local varieties of maize might associate with nitrogen-fixing bacteria is not new, but it has been difficult to identify such a variety and demonstrate that this nitrogen-fixing association actually contributes to nitrogen nutrition of the plant," says Prof. Bennett. "Our interdisciplinary research team has been working on this for nearly a decade."