Fueling ethanol production while protecting water quality

Dried distiller’s grains, a by-product of ethanol production, is being used in animal feeds, particularly for dairy and beef. Dried distiller’s grains contain high concentrations of P and may elevate manure P (and N) content, even when less than 20% of the animals’ diets. This may erode efforts to reduce ration and manure P and will make government feed management programs more expensive and less attractive to farmers. The use of wet distiller’s grains as feed near ethanol facilities avoids the cost of drying the distiller’s grains but requires co-location of animal operations, which will concentrate manure production, often far from grain production, making effective manure use as a fertilizer more difficult and expensive.

Cellulosic fuel stocks from perennials such as switchgrass and woody materials also have the potential to produce ethanol. While cellulosic feedstock production, storage, handling and conversion technology still limit production, a viable cellulosic ethanol industry could reduce dependence on grain and provide water quality and other environmental benefits (such as C sequestration and wildlife habitat). For example, switchgrass, a warm-season perennial prairie grass, produces large amounts of biomass for feedstock, loses very little N and P compared to corn, and stores C in its extensive root system.

The full article is available for no charge for 30 days following the date of this summary. View the abstract at http://jeq.scijournals.org/cgi/content/abstract/37/2/318.

The Journal of Environmental Quality, http://jeq.scijournals.org is a peer-reviewed, international journal of environmental quality in natural and agricultural ecosystems published six times a year by the American Society of Agronomy (ASA), Crop Science Society of America (CSSA), and the Soil Science Society of America (SSSA). The Journal of Environmental Quality covers various aspects of anthropogenic impacts on the environment, including terrestrial, atmospheric, and aquatic systems.

The Soil Science Society of America (SSSA) www.soils.org is a scientific society based in Madison, Wisconsin, which helps its 6,000+ members advance the disciplines and practices of soil science by supporting professional growth and science policy initiatives, and by providing quality, research-based publications and a variety of member services.