Napiergrass could be a viable biofuel crop in the southern tier of Southeastern states, a USDA-ARS study shows.

Also known as elephant grass, this tall-growing subtropical perennial is fairly drought-tolerant, grows well on marginal land and filters nutrients out of runoff in riparian areas, says Bill Anderson, a geneticist at USDA’s Crop Genetics and Breeding Research Unit in Tifton, GA.

As part of a nationwide search for alternative biofuel crops, he and his colleagues compared the biomass yields and soil nutrient requirements of napiergrass, energy cane, switchgrass and giant reed in a four-year study.

“Energy cane and napiergrass are not as cold tolerant as switchgrass, but they do offer advantages in areas where they can be produced, such as continued vegetative growth until killing frost,” Anderson says.

The researchers are evaluating napiergrass with an eye toward improving yields, useable fiber content and disease resistance. They’re also testing different soil amendments, such as chicken litter, variable rates of inorganic fertilizer and winter cover crops, and comparing those with no use of inputs.

“In one test, we’re looking at six different rates of fertilizer use as well as different irrigation levels.” he says. “We’ve also looked at the times of planting and harvest, comparing yields in areas where poultry litter was used and where synthetic fertilizer was used.”

Preliminary findings show that yields are sufficient without irrigation and that there is little difference in yield when poultry litter is used instead of inorganic fertilizer.