Getting to the Root

As climate change worsens global drought conditions, hindering crop production, the search for ways to capture and store the atmospheric carbon causing the phenomenon has intensified.

Penn State researchers have developed a new high-tech tool that could spur changes in how crops withstand drought, acquire nitrogen and store carbon deeper in soil.

The researchers, who published their findings in Crop Science, describe a process for accurately estimating the depth of plant roots by scanning leaves with X-ray fluorescence spectroscopy, a process that detects chemical elements in the foliage. The method recognizes that roots take up elements they encounter, depending on the depth they reach, and a correlation exists between chemical elements in the leaves and root depth.

The new technology is the subject of a provisional patent application by Penn State because it promises to speed the plant-breeding process, according to research team leader Jonathan Lynch, distinguished professor of plant nutrition. The ability to measure the depth of plant roots without excavating them is a game-changing technology, he said.

"We've known about the benefits of deeper-rooting crops for a long time but the problem has been how to measure root depth in the field," Lynch said. "To breed deeper-rooted crops, you need to look at thousands of plants. Digging them up is expensive and time-consuming. Everybody wants deep-rooted crops — but until now, we didn't know how to get them."

—Jeff Mulhollem