New research from USDA's Agricultural Research Service continues to unlock the carbon sequestering potential of switchgrass compared to corn in ethanol production.
Mark Liebig, soil scientist for ARS's Northern Great Plains Research Laboratory in
While previous studies only measured carbon retained in the top foot of soil, Liebig, rangeland scientist Holly Johnson sampled down to four feet beneath fields of switchgrass, corn and wheat on 42 farms in
Switchgrass - a warm-season perennial indigenous to
Liebig found that switchgrass fields had an average of about seven tons more soil carbon per acre than nearby corn and wheat fields. Greater soil carbon under switchgrass was observed at all depths, but it was most pronounced at one to three feet down - a depth in the soil profile where switchgrass has more root biomass than corn or wheat. Switchgrass roots grow as long as eight feet, compared to feet for corn and wheat.
The sites Liebig and Johnson studied are representative of about 74 million acres of the Northern Plains and northern