The original version of this article, by Susan Moran, appeared on Ensia.

Lean and towering at 6 feet 5 inches, Ken Giller blends right into the rows of climbing beanstalks he is examining on this blisteringly hot spring day in Buhoro, a village in northern Rwanda. Local farmers who have been growing various varieties of beans bred for high yields and other desirable traits proudly show him their plots on the terraced hillside.

“Aren’t they beautiful?” Giller beams as he plucks a bean shoot from the red soil and slices open a marble-sized nodule on its root.

Giller, a professor of plant production systems at Wageningen University in the Netherlands, understands as much as anyone the critical role climbing beans, common beans, soybeans, and other legumes can play in nourishing the planet’s burgeoning population in an environmentally sustainable way.

His book, Nitrogen Fixation in Tropical Cropping Systems, is considered a bible of sorts for 
researchers and agricultural extension workers. It explains how symbiotic Rhizobia soil bacteria that live in nodules in the roots of legumes “fix” nitrogen – that is, convert nitrogen gas in the atmosphere into a form plants (and, eventually, the animals that eat plants) can use to make DNA and protein molecules on which all life depends.

Continue reading on Ensia.

Video Credit: “N2Africa Reading the Landscape Audio Slideshow Rwanda,” courtesy of N2Africa.