top of page

Comparison of Biofuel Systems Experiment (COBS)

COBS is a large, multi-investigator, long-term, cropping systems experiment. Click here to go to the COBS experiment website.


My research focus in that experiment is comparing the growth and biomass production of fertilized and unfertilized prairies and continuous corn systems; examining the effects of nitrogen fertilization on prairie diversity, development, and feedstock characteristics; and determining the estimated biofuel yields and net energy balances of all of the cropping systems.​

The featured photograph is an aerial of the COBS experiment taken by Tom Schultz in August 2009.  COBS is located at the South Reynoldson Farm in Boone County, IA.


Peer-reviewed articles from the COBS Experiment:


Jarchow, M.E. and M. Liebman (2013)xNitrogen fertilization increases diversity and productivity of prairie communities used for bioenergy. Global Change Biology Bioenergy 5(3):281-289.

Jarchow, M.E., M. Liebman, S. Dhungel, R. Dietzel, D. Sundberg, R.P. Anex, M.L. Thompson, and T. Chua (2015) Trade-offs in agronomic, energetic, and environmental performance of corn and prairie bioenergy cropping systems. Global Change Biology Bioenergy 7(1):57-71.


Dietzel, R., M.E. Jarchow, and M. Liebman (2015) Above- and below-ground growth, biomass, and nitrogen use in maize and reconstructed prairie cropping systems. Crop Science 55:1-14.


Daigh, A.L.M., X. Zhou, M.J. Helmers, C.H. Pederson, R. Horton, M. Jarchow, and M. Liebman (2015) Subsurface drainage nitrate and total reactive phosphorus losses in bioenergy-based prairies and corn systems. Journal of Environmental Quality, DOI 10.2134/jeq2015.02.0080.


Dietzel, R., M. Liebman, R. Ewing, M. Helmers, R. Horton, M. Jarchow, and S. Archontoulis (2015) How efficiently do corn- and soybean-based cropped systems use water? A systems modeling analysis. Global Change Biology, DOI 10.1111/gcb.13101.

Nichols, V.A., F. E. Miguez, M. E. Jarchow, M. Z. Liebman, and B. S. Dien (2014) Comparison of cellulosic ethanol yields from Midwestern maize and reconstructed tallgrass prairie systems managed for bioenergy. Bioenergy Research, DOI 10.1007/s12155-014-9494-9.


You Tube videos featuring the COBS Experiment:

Comparison of Biofuel Systems, Personnel

Comparison of Biofuel Systems

bottom of page