Management controls the net greenhouse gas outcomes of growing bioenergy feedstocks on marginally productive croplands

Authors

Virginia L. Jin, USDA-ARS, Lincoln, NEFollow
Marty Schmer, USDA, Agricultural Research Service, University of Nebraska-LincolnFollow
Catherine E. Stewart, Soil Management and Sugarbeet Research Unit, USDA-ARS, Fort Collins, COFollow
Robert B. Mitchell, Agricultural Research Service, USDAFollow
Candiss O. Williams, USDA-NRCSFollow
Brian J. Wienhold, Soil and Water Conservation Research Unit, USDA-ARSFollow
Gary Varvel, USDA-ARS, University of Nebraska-LincolnFollow
Ronald F. Follett, United States Department of AgricultureFollow
John Kimble, USDA-ARS
Kenneth P. Vogel, University of Nebraska-LincolnFollow

Date of this Version

12-18-2019

Citation

Jin et al., Sci. Adv. 2019; 5 : eaav9318

Comments

No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).

Abstract

Bio-based energy is key to developing a globally sustainable low-carbon economy. Lignocellulosic feedstock production on marginally productive croplands is expected to provide substantial climate mitigation benefits, but long-term field research comparing greenhouse gas (GHG) outcomes during the production of annual versus perennial crop-based feedstocks is lacking. Here, we show that long-term (16 years) switchgrass (Panicum virgatum L.) systems mitigate GHG emissions during the feedstock production phase compared to GHG-neutral continuous corn (Zea mays L.) under conservation management on marginally productive cropland. Increased soil organic carbon was the major GHG sink in all feedstock systems, but net agronomic GHG outcomes hinged on soil nitrous oxide emissions controlled by nitrogen (N) fertilizer rate. This long-term field study is the first to demonstrate that annual crop and perennial grass systems respectively maintain or mitigate atmospheric GHG contributions during the agronomic phase of bioenergy production, providing flexibility for land-use decisions on marginally productive croplands.