The hotter it gets, the better eastern gamagrass grows. That's according to Agricultural Research Service scientists at the ARS Henry A. Wallace Beltsville (Md.) Agricultural Research Center.
This means the plants not only could produce higher yields, but also store more carbon and therefore help mitigate the effects of high atmospheric carbon dioxide (CO2) levels associated with global warming.
ARS plant physiologists Donald Krizek, Dennis Gitz and V.R. Reddy and soil scientist Jerry Ritchie have obtained the first experimental proof that eastern gamagrass may out-compete other plants and store more carbon in a hotter climate.
The scientists simulated global warming conditions in outdoor climate-controlled SPAR (Soil-Plant-Atmosphere Research) chambers. They tested the plants at the current level of atmospheric CO2 — 370 parts per million — as well as at double that amount, the level expected around 2100.
Their experiments show that when temperatures were increased from 68 degrees Fahrenheit during the day and 57 degrees F at night to 95 degrees F in the daytime and 84 degrees F at night, eastern gamagrass plants could triple their carbon storage.
The plants' leaves were bigger and contained twice as much nitrogen, raising their protein content. Temperature had far more effect on plant growth than C02 level.
Eastern gamagrass is often called "Queen of the Grasses" because it has so many good qualities. A hardy, warm-season grass, it not only tolerates and grows in marginal soils that are acid, compacted and waterlogged, it actually improves them. Eastern gamagrass also seems to withstand hot, dry conditions by closing the stomates on its leaves during the day to reduce water use.
At a time of year when cool-season grasses go dormant, eastern gamagrass provides high-yielding forage that is as nutritious as alfalfa. It also has potential for use in conservation plantings, as a bioenergy crop, and for making high-fiber flour.
Read more about this research in the September 2005 issue of Agricultural Research magazine, online at: www.ars.usda.gov/is/AR/archive/sep05/carbon0905.htm
ARS is the U.S. Department of Agriculture's chief scientific research agency.