Functional group and fertilization affect the composition and bioenergy yields of prairie plants

Abstract

Prairies used for bioenergy production have potential to generate marketable products while enhancing environmental quality, but little is known about how prairie species composition and nutrient management affect the suitability of prairie biomass for bioenergy production. We determined how functional-group identity and nitrogen fertilization affected feedstock characteristics and estimated bioenergy yields of prairie plants, and compared those prairie characteristics to that of corn stover. We tested our objectives with a field experiment that was set up as a 5 9 2 incomplete factorial design with C 3 grasses, C 4 grasses, legumes, and multi-functionalgroup mixtures grown with and without nitrogen fertilizer; a fertilized corn treatment was also included. We determined cell wall, hemicellulose, cellulose, and ash concentrations; ethanol conversion ratios; gross caloric ratios; aboveground biomass production; ethanol yields; and energy yields for all treatments. Prairie functionalgroup identity affected the biomass feedstock characteristics, whereas nitrogen fertilization did not. Functional group and fertilization had a strong effect on aboveground biomass production, which was the major predictor of ethanol and energy yields. C 4 grasses, especially when fertilized, had among the most favorable bioenergy characteristics with high estimated ethanol conversion ratios and nongrain biomass production, relatively high gross caloric ratios, and low ash concentrations. The bioenergy characteristics of corn stover, from an annual C 4 grass, were similar to those of the biomass of perennial C 4 grasses. Both functional-group composition and nitrogen fertility management were found to be important in optimizing bioenergy production from prairies.

Intermediate Wheatgrass Grain and Forage Yield Responses to Nitrogen Fertilization

“…Theoretical ethanol potential of switchgrass when managed at AONR for biomass yield ranged from an estimated 362 to 401 L Mg -1 , which is less than other reported values (Schmer et al, 2012;Jarchow et al, 2012;Jungers et al, 2015b). When measured on an area basis, ethanol yields were greater for switchgrass compared to TLI-C2 and Rush (Fig.…”

Spatial and Temporal Dynamics of Soil‐Surface Carbon Dioxide Emissions in Bioenergy Corn Rotations and Reconstructed Prairies

“…5). This is attributed to the higher quantity of vegetative biomass in the crop canopy intercepting solar radiation (Jarchow and Liebman, 2013;Jarchow et al, 2012;Morris, 1989). Among the continuous corn systems, CCW was significantly lower in T soil than CC on only 5 of the 47 sample dates (i.e., 11%) with most occurrences during May.…”

Switchgrass Biofuel Production on Reclaimed Surface Mines: II. Feedstock Quality and Theoretical Ethanol Production

“…This can be due to precipitation [15], temperature [1], and management [14]. Within-field variation and small changes in soil properties do not seem to affect switchgrass composition because individual fields are subject to similar temperatures, precipitation, and harvest management [29].…”