BioEnergy Research

, Volume 7, Issue 4, pp 1550–1560

Comparison of Cellulosic Ethanol Yields from Midwestern Maize and Reconstructed Tallgrass Prairie Systems Managed for Bioenergy

  • V. A. Nichols
  • F. E. Miguez
  • M. E. Jarchow
  • M. Z. Liebman
  • B. S. Dien
Article

DOI: 10.1007/s12155-014-9494-9

Cite this article as:
Nichols, V.A., Miguez, F.E., Jarchow, M.E. et al. Bioenerg. Res. (2014) 7: 1550. doi:10.1007/s12155-014-9494-9

Abstract

Maize- and prairie-based systems were investigated as cellulosic feedstocks by conducting a 9 ha side-by-side comparison on fertile soils in the Midwestern United States. Maize was grown continuously with adequate fertilization over years both with and without a winter rye cover crop, and the 31-species reconstructed prairie was grown with and without spring nitrogen fertilization. Both maize stover and prairie biomass were harvested in the fall. We compared amounts of cellulosic biomass produced and harvested, carbohydrate contents as measured by both dietary and detergent methods, and estimated cellulosic ethanol yields per hectare. From 2009–2013, the cropping system with the largest non-grain biomass yield was fertilized prairie, averaging 10.4 Mg ha−1 year−1 aboveground biomass with average harvest removals of 7.8 Mg ha−1 year−1. The unfertilized prairie produced 7.4 Mg ha−1 year−1 aboveground biomass, with average harvests of 5.3 Mg ha−1 year−1. Lowest cellulosic (non-grain) biomass harvests were obtained from continuous maize systems, averaging 3.5 Mg ha−1 year−1 when grown with, and 3.7 Mg ha−1 year−1 when grown without a winter rye cover crop, respectively. Unfertilized prairie biomass and maize stover had equivalent dietary-determined potential biomass ethanol yields at 330 g ethanol kg−1 dry biomass, but fertilized prairie was lower at 315. The detergent method did not accurately capture these differences. Over the five-year period of the experiment, unfertilized and fertilized prairie systems averaged 810 and 1,790 L potential cellulosic ethanol ha−1 year−1 more than the maize systems, respectively. Differences in harvested biomass accounted for >90 % of ethanol yield variation.

Keywords

Tallgrass prairie Cellulosic ethanol Grassland Iowa Dietary Detergent 

Abbreviations

US

United States

Mg

mega-gram, 1,000 kg

Ha

hectare, 10,000 m2

Yr

year

N

nitrogen

STRIPS

Science-based Trials of Rowcrops Integrated with Prairies

DTG

Detergent

NREL

National Renewable Energy Laboratory

LCAs

Life cycle assessments

UAN

Urea ammonium nitrate

CC

Continuous maize cropping system

CCW

Continuous maize grown with a winter rye cover crop cropping system

P

Un-fertilized prairie system

PF

N-fertilized prairie system

°C

Degrees Celsius

BEY

Biomass ethanol yield

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  • V. A. Nichols
    • 1
  • F. E. Miguez
    • 1
  • M. E. Jarchow
    • 2
  • M. Z. Liebman
    • 1
  • B. S. Dien
    • 3
  1. 1.Department of AgronomyIowa State UniversityAmesUSA
  2. 2.Sustainability Program and Department of BiologyUniversity of South DakotaVermillionUSA
  3. 3.USDA Agricultural Research ServicePeoriaUSA

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