Fertitta-Roberts, C. and Spatari, S. and Grantz, D.A. and Jenerette, G.D. (2017) Trade-offs across productivity, GHG intensity, and pollutant loads from second-generation sorghum bioenergy. Global Change Biology Bioenergy, 9 (12). pp. 1764-1779.
![[img]](http://eprints.icrisat.ac.in/style/images/fileicons/application_pdf.png) |
PDF
- Published Version
Restricted to ICRISAT researchers only Request a copy |
Abstract
Greenhouse gas (GHG) intensity is frequently used to assess the mitigation potential of biofuels; however, failure to quantify other environmental impacts may result in unintended consequences, effectively shifting the environmental burden of fuel production rather than reducing it. We modeled production of E85, a gasoline/ethanol blend, from forage sorghum (Sorghum bicolor cv. photoperiod LS) grown, processed, and consumed in California’s Imperial Valley in order to evaluate the influence of nitrogen (N) management on well-to-wheel (WTW) environmental impacts from cellulosic ethanol. We simulated 25 N management scenarios varying application rate, application method, and N source. Life cycle environmental impacts were characterized using the EPA’s criteria for emissions affecting the environment and human health. Our results suggest efficient use of N is an important pathway for minimizing WTW emissions on an energy yield basis. Simulations in which N was injected had the highest nitrogen use efficiency. Even at rates as high as 450 kg N ha 1, injected N simulations generated a yield response sufficient to outweigh accompanying increases in most N-induced emissions on an energy yield basis. Thus, within the biofuel life cycle, trade-offs across productivity, GHG intensity, and pollutant loads may be possible to avoid at regional to global scales. However, trade-offs were seemingly unavoidable when impacts from E85 were compared to those of conventional gasoline. The GHG intensity of sorghum-derived E85 ranged from 29 to 44 g CO2 eq MJ 1, roughly 1/3 to 1/2 that of gasoline. Conversely, emissions contributing to local air and water pollution tended to be substantially higher in the E85 life cycle. These adverse impacts were strongly influenced by N management and could be partially mitigated by efficient application of N fertilizers. Together, our results emphasize the importance of minimizing on-farm emissions in maximizing both the environmental benefits and profitability of biofuels.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | Air and water pollutant loads, Biofuel sustainability, Cellulosic ethanol, Energy yield, Environmental impacts, Feedstock management, GHG intensity, Life cycle assessment (LCA), Nitrogen use efficiency |
| Author Affiliation: | Department of Botany and Plant Sciences, University of California, Riverside, CA 92512, USA |
| Subjects: | Plant Production |
| Divisions: | Sorghum |
| Depositing User: | Mr B Krishnamurthy |
| Date Deposited: | 13 Dec 2017 11:16 |
| Last Modified: | 13 Dec 2017 11:16 |
| Official URL: | http://dx.doi.org/10.1111/gcbb.12471 |
| URI: | http://eprints.icrisat.ac.in/id/eprint/15271 |
Actions (login required)
 |
View Item |
