BioFuels Journal

BFJ.com Podcast with ARS Soil Scientist Dr. Douglas Karlen on Impact of Corn Stover Removal for Cellulosic Ethanol on Soil Quality

Dr. Douglas Karlen of the USDA Agicultural Research Service (ARS) lab in Ames, IA discussed the research to remove corn stover or just cobs from the soil for cellulosic ethanol and the impact on the soil.

Podcast Highlights

Crop residue is not trash

"That crop residue, that corn stover that's out there is not a trash. Residue has a multitude of functions. As we approached removing that stover, we have to think about what it means to that soil."

Keys to think about

"A big key to this residue removal is looking at our tillage, our rotation, our landscape, our plant population, our productivity levels, all of these factors together."

Rule of thumb

"You can assume an equal number of dry pounds per stover. At 150 bushels per acre, you need all that stover. As you move up the yield curve and produce more bushels of corn, you've got more stover."

Removing cobs only?

"We are just initiating research to give you a measured answer to that question. We are going to initiate a series of replicated plots at the POET site in Emmetsburg, IA."

Projections

"Preliminary data in 2007 at 8 locations across the U.S., suggest between 15 and 20% of plant biomass is weight attributed to the cob. You should be feeding the soil a reasonable amount of carbon input to sustain the soil. You may want to couple this with the least amount of tillage."

Biography

Dr. Douglas Karlen is supervisory soil scientist with the USDA-Agricultural Research Service (ARS) at the National Soil Tilth Laboratory (NSTL) in Ames, IA.

He has been with the USDA-ARS for 29 years and currently serves as research leader for the soil and water quality research unit at the NSTL.

Dr. Karlen also serves as co-leader for the ARS Renewable Energy Assessment Project (REAP) team, a multi-location effort focusing on sustainability of harvesting crop residues for bioenergy and is currently service on a National academy of Sciences Panel focused on “Alternative Liquid Transportation Fuels.”

Dr. Kareln is a native of Wisconsin and has his B.S., M.S., and PhD. Degrees from the University of Wisconsin, Madison, Michigan State University and Kansas State University, respectively.

He is author or co-author of 158 refereed journal article sand more than 100 refereed proceedings, book chapters, and non-technical publications.

Dr. Karlen is a Fellow of the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

He is also recognized as an adjunct Professor in the Agronomy Department at Iowa State University and by the Soil, Crop, and Entomology Department at Clemson University.

For more information, call 515-294-3336.