Producing Cellulosic Ethanol Without Soil Damage

Renewable Energy World: "In the Midwest, 100 to 150 millon tons of corn stover -- crop residue -- is now left on fields to prevent erosion and return nutrients to soil. Now corn stover is being eyed as a possible source of cellulose for biofuel production. But the costs and benefits of harvesting stover need to be determined.

After pretreatment and fermentation screening, they found that the resulting ethanol yields between the normal-cut and high-cut top harvests were indistinguishable. This suggests that normal-cut stover harvest -- characterized by convenience and speed, acceptable stover water content, and potentially lower processing costs -- appears to give producers their best stover harvest option for biofuels.

'Crop residue is not just trash,' says soil scientist Doug Karlen, who works at the ARS National Soil Tilth Laboratory in Ames, Iowa. 'We need to find ways to develop site-specific practices for managing corn stover removal-not a ‘big-box' approach to soil management. With the right approach, corn stover can have bioenergy benefits for U.S. consumers and producers alike.'"