Field-to-farm gate greenhouse gas emissions from corn stover production in the Midwestern US

JOURNAL OF CLEANER PRODUCTION

卷:226

Article

Locker, C. Rebecca¹  Torkamani, Sarah¹  Laurenzi, Ian J.¹  Jin, Virginia L.²  Schmer, Marty R.²  Karlen, Douglas L.³ 

[1] ExxonMobil Res & Engn Co, Corp Strateg Res, 1545 Route 22E, Annandale, NJ 08801 USA

[2] Univ Nebraska Lincoln East Campus, USDA ARS, 251 Filley Food Ind Complex, Lincoln, NE 68583 USA

[3] USDA ARS, NLAE, 1015 N Univ Blvd, Ames, IA 50011 USA

关键词: Life-cycle assessment;    Corn stover;    Greenhouse gases;    Bioenergy;    Biofuel;   

DOI  :  10.1016/j.jclepro.2019.03.154

来源: Elsevier

【 摘 要 】

Measured field data were used to compare two allocation methods on life cycle greenhouse gas emissions from corn (Zea mays L) stover production in the Midwest U.S. We used publicly-available crop yield, nitrogen fertilizer, and direct soil nitrous oxide emissions data from the USDA-ARS Resilient Economic Agricultural Practices research program. Field data were aggregated from 9 locations across 26 site-years for 3 stover harvest rates (no removal; moderate removal 3.1 Mg ha(-1); high removal 7.2 Mg ha(-1)) and 2 tillage practices (conventional; reduced/no-till). Net carbon uptake by crops was computed from measured plant carbon content. Monte Carlo simulations sampled input distributions to assess variability in farm-to-gate GHG emissions. The base analysis assumed no change in soil organic carbon stocks. In all cases, net CO2 uptake during crop growth and soil-respired CO2 dominated system emissions. Emissions were most sensitive to co-product accounting method, with system expansion emissions 15% lower than mass allocation. Regardless of accounting method, lowest emissions occurred for a moderate removal rate under reduced/no-till management. The absence of correlations between N fertilization rate and stover removal rate or soil N2O emissions in this study challenges the use of such assumptions typically employed in life cycle assessments Storage of all carbon retained on the field as SOC could reduce emissions by an additional 15%. Our results highlight how variability in GHG emissions due to location and weather can overshadow the impact of farm management practices on field-to-farm gate emissions. (C) 2019 Published by Elsevier Ltd.

【 授权许可】

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