Corn Cob Ethanol Looks OK for Soil

Study funded by POET indicates that fertilizer rates won't have to rise.

Published on: May 28, 2009

POET says that research it funded at Iowa State University shows it is economically and environmental okay to make ethanol out of corn cobs.


POET is making ethanol from corn cobs at a pilot plant in Scotland, S.D., and is planning to go commercial with the process at its Emmetsburg, Iowa, plant in 2011. The company also operates several other plants in South Dakota and corn cob ethanol could be added to those facilities.


Removing corn cobs from fields appears to have no substantial impact on soil nutrient content, according to the ISU study.


Results from the first year of the study, conducted on a test field near Emmetsburg, indicate that fertilizer treatment for a field in which cobs have been removed would be almost identical to treatment of a field in which cobs were not removed.


ISU researchers will continue their work this year on the test plots, compiling more data to help farmers manage their land well while taking advantage of an additional revenue source from their fields.


"This information reinforces previous research showing that corn cobs are a sustainable, environmentally friendly feedstock for producing cellulosic ethanol, and removing them from the field will not alter soil quality," says Scott Weishaar, POET vice president of commercial development.


To see a documentary about POET's pilot cellulosic ethanol plant, go to