WITH an eye toward sustainable practices, the U.S. Department of Agriculture announced last month a federal/private conservation collaboration to develop voluntary standards for harvesting agricultural residues to be used for cellulosic ethanol production.
The joint agreement between USDA's Natural Resources Conservation Service (NRCS) and DuPont will work to safeguard natural resources on private lands used to produce potential biofuel crops.
Under the memorandum of understanding, NRCS will provide conservation planning assistance for farmers who supply bio-based feedstocks to biorefineries as the industry reaches commercial scale.
DuPont, meanwhile, will develop a process to work with cooperating farms on sustainable harvest practices to keep the soil in the field and out of waterways, promote healthier soils and provide for the efficient use of nutrients.
The first plant involved in the agreement will be DuPont's cellulosic facility near Nevada, Iowa. When construction is completed, the plant is expected to produce 30 million gal. of ethanol per year from cellulosic residues harvested in a 30-mile radius of the facility.
NRCS will assist farmers in drafting conservation plans to ensure sustainable harvesting of corn crop residues while promoting natural resource conservation and land productivity. The plans are voluntary documents written in cooperation with farmers to help them protect natural resources while supporting their economic sustainability.
"Working with farmers is critical to maximizing the land's productivity and protecting natural resources," DuPont executive vice president Jim Borel said. "With this new collaboration, we have a partner in NRCS to ensure that the collection of corn stover for the production of cellulosic renewable fuel makes sense for an individual grower's operation and the land they farm."
New energy crops
Meanwhile, researchers at The Ohio State University are studying other crops with the potential to feed cellulosic ethanol production.
They are evaluating the potential of a variety of grasses, trees and shrubs for their suitability to different growing conditions, their biomass yield and their potential to become value-added crops for farmers in the region.
"These crops can grow on marginal land and will not take away good land from food production," Rafiq Islam, a soil, water and bioenergy specialist at Ohio State, said. "Our idea is to use degraded soils and land not suitable to grow food crops for bioenergy production."
Islam said several bioenergy crop trials have been conducted in southern Ohio, where hilly terrain and reclaimed strip mines abound. Plants under study include switchgrass, various prairie grasses, miscanthus, hybrid willow, sudan sorghum grass, sweet sorghum and guayule.
A study of seven varieties of miscanthus and three varieties of switchgrass found that miscanthus can yield as much as 9.6 tons of biomass per acre, providing ample output with low nutrient requirements and an adaptability to many different soil types and growing environments. Because the crops are perennials, once a stand is established, it will produce for many years before replanting is necessary.