Eastern Gamagrass Surviving Drought

Patches of green in a brown field have put smiles on the faces of Charles Foy and Donald Krizek. The two Agricultural Research Service scientists are excited about eastern gamagrass. This native species was overgrazed into oblivion decades ago--but rediscovered by a Missouri farmer in 1980 during a severe drought.

This “new old grass,” a perennial that grows as high as its relative corn, is again surviving a severe drought this summer in parched fields at ARS’ Beltsville (Md.) Agricultural Research Center. Only about an inch of rain fell from the first of July to mid-August, but the gamagrass has been cut twice. It yielded 6,600 pounds of 14- percent-protein hay per acre, on par with alfalfa. Surrounding corn and soybean plants dried up. But even after two cuttings, some gamagrass is still more than a foot high and shows no drought symptoms.

What gives eastern gamagrass an edge when water is scarce? The scientists say the keys are air-filled root passages called aerenchyma [pronounced air-ENK-a-ma]. With aerenchyma, roots can penetrate so deep they draw water that shallow-rooted plants can’t reach. Eastern gamagrass roots extend down as far as 7 feet, despite a compacted claypan, acid soil, and low-lying areas prone to flooding that would kill many crops.

Foy and Krizek, with colleagues Jerry Ritchie and Ali Sadeghi, plan further studies to see if eastern gamagrass’ deep roots can loosen compacted soils and provide channels for roots of other crops. They also want to test the grass in buffer strips to reduce soil erosion.

To see a photo of Beltsville’s eastern gamagrass on the World Wide Web, point your browser to:

http://www.ars.usda.gov/is/graphics/photos/k7820-6.htm

A feature story on aerenchyma appears in the August Agricultural Research magazine. It’s on the web at:

http://www.ars.usda.gov/is/AR/archive/aug97/aerenchyma0897.htm

Scientific contact: Scientific contact: ARS Climate Stress Laboratory, Beltsville, Md.--Donald Krizek, phone (301) 504- 5324, fax 504-6626, [email protected]; and Charles Foy, phone (301) 504-5522, fax 504- 7521.